Maltese ex-EU commissioner could face EU court

"A possible reaction from the commission will depend on a range of factors," said the spokesperson.

This includes the gravity of the breach, its consequences, the circumstances of the breach, and if it was a deliberate or negligent breach, he added.

Dalli could face anything from a public slap on the wrist for breaking the commission's code of conduct rules to having the European Court of Justice strip his pension rights.

A trove of leaked documents from the International Consortium of Investigative Journalists (ICIJ) known as the Pandora Papers found that Dalli owned an offshore company in the British Virgin Islands, which he had opened in 2006 but never declared.

Dalli has since denied any wrongdoing, noting that he set up the firm, Westmead Overseas, to hold equity in a project that "never materialised, and the company was not used."

But European Commissioners are obliged to declare any positions held in the last 10 years as well as their financial interests.

And Dalli was EU commissioner for health from 2010 until late 2012, before being forced out office in a tobacco-lobbying scandal.

Dalli has consistently maintained his innocence over the lobbying affair, which included allegations of a €60m bribe to ease an EU-wide sale ban on snus, a mouth tobacco popular in Sweden.

Olaf, the EU's anti-fraud office, at the time found "unambiguous and converging circumstantial pieces of evidence" linking Dalli to the bribery affair via his former political campaign canvasser and restauranteur Silvio Zammit.

Although no payments were made, Dalli is still set to be charged in Malta over the allegations.

The scandal further erupted to include unrelated scams that saw US pensioners lose all their savings in a Ponzi-scheme involving Dalli's daughters and an American evangelical swindler known as Lady Bird, since deceased.

The daughters have denied any wrongdoing in a case that is still ongoing.

Dalli's EU pension is based on the last basic salary as commissioner and calculated on the period of service with an acquisition rate of 4.275 percent per year.