Until last week, anyone wanting to know the ultimate owner of an EU-based company could consult databases held by member states. This public access has helped expose myriad abuses, including by a Czech prime minister and a Lebanese central bank governor.

But, in a ruling last week in a case centred on privacy and data protection, the Court of Justice of the EU has in effect shut such registers to public view.

Transparency campaigners described Tuesday’s decision as a surprising and drastic regression in efforts to tackle money laundering and the abuse of shell companies. The move is likely to have a wider chilling effect, they added.