Offshore leaks in due diligence: what ICIJ data proves, and what it does not

Journalistic leak datasets are among the strongest open sources available for checking who stands behind a company. They are also the easiest to misuse. This article covers what the datasets contain, where they earn their place in a check, how the search is actually run, and the three errors that turn a powerful source into a false conclusion.

What the datasets actually are

The International Consortium of Investigative Journalists publishes and structures material from a series of large financial leaks. Five archives sit behind a single free search interface, with no registration and no fee.

Between them the archives name entities, the officers and shareholders attached to them, the intermediaries who incorporated them and the addresses used. That combination is what makes them useful: they connect a name to a structure, which is exactly the connection a corporate register in a secrecy jurisdiction is designed not to publish.

Where leak data earns its place

For a buyer inside the European Union this matters more than it did five years ago, and for an unexpected reason. In November 2022 the Court of Justice of the European Union struck down the provision of the anti-money-laundering directive that had opened beneficial ownership registers to the general public. Member states responded unevenly. Some kept their registers effectively open, among them Poland, Estonia, Latvia, Bulgaria and Romania. Others closed public access and now admit only those who can demonstrate a legitimate interest, or refuse outsiders altogether — the Netherlands, Ireland, Cyprus, France, Italy, Spain, Belgium, Lithuania, Slovakia and Czechia among them.

The practical consequence is that an ownership chain running into one of the closed jurisdictions can no longer be resolved by looking it up. Leak data does not close that gap, but it is one of the few open sources that can put a name against a structure the register will not disclose — provided the structure existed at the time of the leak.

The same logic applies outside the EU. In jurisdictions where ownership, courts or property records are closed to third parties, the leak archives are sometimes the only public place a nominee arrangement is documented at all.

How the search is run

Step one is where most self-run searches fail. A company incorporated in Ukraine, Poland or Germany will rarely appear in an offshore archive under its own name. The person who owns it may well appear, attached to a structure in a third country.

Three mistakes that make the data useless

Treating a hit as proof of wrongdoing. Offshore structures are lawful instruments of international business, used for financing, joint ventures, estate planning and holding arrangements that have nothing to hide. Appearing in an archive is not an allegation. What matters is the context: which jurisdiction, incorporated when, alongside whom, and does the counterparty account for it when asked. A hit changes what you ask about. It does not answer anything by itself.

Treating an absence as a clearance. This is the more expensive error. Each archive is a leak from specific providers at a specific moment. Hundreds of other incorporation agents have never been the subject of a leak, and nothing obliges them to be. Absence from the archives establishes only that this counterparty was not a client of those particular providers before those particular dates. It says nothing about whether offshore structures exist.

Searching only the company name. Covered above, and worth repeating because it is the single most common reason a search comes back empty when it should not have.

The limit nobody mentions: the data is frozen

Every archive reflects the state of affairs on the date the material left the provider. The most recent, the Pandora Papers, dates from 2021. A structure created in 2023 to hold assets ahead of a sanctions designation will not be there, and never will be.

This is why leak data is a supplement and not a method. A check that relies on it alone is reading a photograph of the past. For Ukrainian counterparties the live layer became substantially better on 19 January 2026, when the state corporate register returned to open data with ownership structure and beneficial ownership included — the first time that information had been publicly available since February 2022. The combination is what works: the current register establishes who is declared today, and the archives sometimes show what the declaration leaves out.

What you can do yourself, and when to order a check

The search itself is free and takes minutes. Anyone signing a contract should run the counterparty and its named officers through the archives before committing money — it costs nothing and occasionally changes a decision outright.

What does not scale to a self-check is the interpretation. Establishing whether a hit is a legacy holding structure or an active concealment layer means reconstructing the chain across live registers in several jurisdictions, matching addresses and officers, checking designations against ownership thresholds and reading the timing against events. That is the work a documented report exists to do, and it is where a single unexplained name turns into either a cleared question or a reason not to sign.

Bottom line

The offshore archives are free, genuinely powerful and routinely misread. A hit is a question, not a verdict. A miss is silence, not a clearance. And because the newest archive is now several years old, anything built recently is invisible to it. Use the archives to generate leads, and live registers to resolve them.

Frequently asked questions

Related reading: the patterns these structures are built into, in sanctions evasion through transit jurisdictions, and how ownership is resolved to a person, in who beneficial owners are and why they hide.