Dataharvest 2026 - the European Investigative Journalism Conference

Over the past three years, the Guardian Data Projects team has revealed how private equity firms have increased their share in the childcare sector as well as in the provision of children’s care homes in England. We have also investigated how taxpayers’ money for services that provide support for rape and sexual assault victims ends up in private equity companies. And we have estimated that the UK government has spent billions of pounds in companies that are owned by a private equity group.

Attendees to this session will learn about two methodologies the Guardian built to track down the involvement of private equity firms in the country’s economy and specific sectors. They will also learn about specific resources to find out company data, as well as understand how the Guardian built an automated system to analyse thousands of company records to find the ultimate controlling party for each company group. We will also show how an LLM helped to identify companies owned by a private equity firm, as well as the limitations of using this type of technique.

Drawing on real cross-border investigations from OCCRP's Research & Data team, this session will share the tools, techniques, and workflows the team relies on daily to support hundreds of journalists around the world. From geolocating images and tracking assets to social media investigations and smart browser hacks, this session will offer a practical, field-tested OSINT toolkit.

With shrinking newsroom budgets and a constant stream of "must-have" tools, it's harder than ever for journalists to know what OSINT tools might actually be worth using or paying for. This session cuts through the noise and focuses on what works right now.

Whether conference attendees are new to open-source research or looking for a sharp refresher, they will leave with concrete skills, trusted tools, and time-saving methods they can immediately apply to their own investigations.

In almost all research, we need to uncover information about given individuals: criminals, extremists, corrupt public officials. This workshop focuses on identifying the players in a nasty game, as well as people who can provide valuable information as sources. It delves into investigating their social media accounts, their addresses, and their networks. Details they aim to keep hidden but often fail to.

We will provide strategies, tools and tricks for finding people online. What can email addresses, social media profiles and telephone numbers reveal about a person? How can data leaks, Google reviews, and even apps like Strava offer insights for research? And what do the deceased leave behind? We go beyond abstract methods and present real-world investigation cases: Learn how an investigation can start with nothing more than a name – and end with ringing someone’s doorbell.

The examples include investigations into neo-Nazis and other extremists, police officers and unpeaceful UN peacekeepers, criminal divers, and Secret Service agents kidnapping people.

Everyone listens to audio all the time, yet investigators rarely think of it. This session introduces audio forensics as an often-overlooked OSINT skill. We’ll explore how frequencies, compression, spectrograms, and a touch of physics can be used to authenticate media, detect edits, determine locations, and even prove war crimes. Participants will learn how to calculate a shooter’s distance using bullet speed and the speed of sound, analyse electrical network frequencies, and recognise platform-specific compression. No prior experience in OSINT or extensive knowledge of audio is required — this session is suitable for beginners.

Public archives all over the continent are full of historical stories waiting to be told. From armed conflict and genocide to colonialism or the environment, there are enough subjects that are still very relevant for investigative journalism.

This session will focus on the challenges and, more importantly, the possibilities of working with on-paper archives and analogue photographs. Is it possible to geolocate old prints without metadata or StreetView? Are there any old-school tricks to verify images? And what about AI slop that disguises itself as historical material?

We'll also discuss the importance of historical investigative work, possible subject areas, and useful tools and resources. The session is meant to inspire investigative journalists to dive headfirst into public archives and find relevant stories using their existing skills.

What can you learn from a discarded laptop? In this session, participants will gather in small groups, and each will receive a laptop. They will have 50 minutes to get as much information as possible from the machines, especially about their past owners. Due to the risks to their (past owners') privacy, a clear code of conduct will be read out at the beginning of the session: no personal information contained in the machines will be photographed or shared at any time.

The session organizers will document the strategies developed by each team to investigate and share the results with all participants. The participants' findings are not shared with the room (for privacy reasons). Besides the fun of satisfying naked curiosity, participants will be able to hone their forensics skills on hardware, develop investigative strategies in large amounts of files, and use OSINT techniques to cross-validate information. They will also have to develop team management skills so as to ensure that all team members have access to the data.

Finally, this session will serve us as a reminder to seriously erase data before disposing of hardware. Please note: in order to attend this session, you need to register. The maximum number of participants is capped at 20.

This session will cover how to use trade information for investigative reporting, from the theory behind commercial flows to its application to real investigative cases. The first part of the presentation will focus on the "dictionary" that is crucial to read and interpret trade data. Then, it will explore how to source official customs statistics for free, understand crucial variables in import-export sheets, and find workarounds to expensive third-party commercial providers.

Examples from real investigations will show the power of using trade data in covering topics such as deforestation, sanctions evasion, the military industry, cocaine trafficking, but also much more "ordinary" commercial flows that might be linked to pollution/environmental issues. Throughout the session, participants will be welcome to bring examples of commodities they would like to track and guided in a few hands-on exercises to familiarise themselves with finding and understanding this kind of data.

The session is suitable for beginners. No technical/coding experience is needed, but the participants should be familiar with spreadsheets.

AI-generated scam advertisements have flooded European social media platforms, using deepfake videos, cloned voices, and fabricated news stories to lure thousands of victims into fraudulent investment schemes. While the EU's Digital Services Act (DSA) was designed to curb illegal and harmful content, these scams continue to spread at scale, exposing major gaps in platform enforcement and regulatory oversight.

This session will show how to investigate AI-driven scam ads and platform failure using publicly available tools, leaked material, and EU tech legislation. We will walk through how to find and identify and analyse AI-generated scam ads and deepfake content, use Meta's Ad Library to map scam campaigns, detect duplication and evasion tactics, and estimate scale. The session will also address how to collaborate effectively with civil society organisations and trusted flaggers to monitor platforms and access specialised expertise.

As part of the presentation, we'll also talk about how to investigate the Digital Services Act in practice, including transparency obligations, systemic-risk provisions and reporting mechanisms; how to document and report on failures of enforcement by platforms and public authorities, and how to connect platform-level analysis to human stories, including victims' experiences. That also includes how to responsibly handle leaked messages, call scripts, and fake trading platforms, balancing verification, security and ethical considerations.

The session will include concrete examples and live walkthroughs, showing how journalists can combine platform data, legal frameworks and human sources to hold tech companies and regulators accountable. 

Predictive Markets are on the rise, and with them, easy money for insider knowledge and those who can influence their outcomes. While regulation is slow to catch up, investigations don't have to be. Polymarket is the most well-known of these predictive markets, and one thing that defines it is open data on all exchanges going on in a market.

This session will cover key concepts of Polymarket and the possibilities and limitations of investigating it. It will include basic Python code to extract and analyse its open data, and a new open source user interface tool you can use to quickly understand the market and accounts. In the end, we will learn techniques to identify suspicious actors from a few example markets.

Although some code will be shared during the session, you don't need to have a working knowledge of Python to participate.