Guy Verhofstadt sat on the board of Belgian shipping firm Exmar, which was named in the Paradise Papers | Paul Faith/AFP via Getty Images Guy Verhofstadt linked to Paradise Papers company Belgian shipping firm Exmar was mentioned in the leaked documents.

Guy Verhofstadt, the liberal group leader in the European Parliament, came under fire Tuesday over his links to a firm mentioned in the Paradise Papers.

Verhofstadt sat on the board of Exmar — a Belgian shipping firm — which used an offshore company mentioned in the recent Paradise Papers leaked documents about circumventing tax rules through offshore investments.

The revelations about Verhofstadt were made public by Belgium's far-left Workers' Party on Tuesday evening.

The former Belgian prime minister sat on Exmar Group's board of directors between 2010 and 2016. Its annual reports show he received €60,000 per year. The company's board of directors also includes Howard Gutman, former U.S. President Barack Obama's ambassador to Belgium.

The Paradise Papers mention Exmar Offshore in Bermuda, part of the Exmar Group. Set up in 1997, Exmar Offshore provides energy services.

Nicolas Saverys, chief executive officer of Exmar Group, described Exmar Offshore, a group of separate but related companies, as "an engineering company headquartered in Houston, Texas."

According to Saverys, the Bermuda-based company is extremely limited in scope, adding that "it is a dormant company" which carries out minimal activities.

Exmar Offshore has a limited company in Bermuda, its main company in the U.S., a services division in Luxembourg and a limited company in Belgium, its most recent annual report shows.

Saverys said "it is the duty of a company executive or manager to find the least-taxable route" and described recent revelations about offshore taxation optimization as a "witch hunt."

Peter Mertens, president of the Workers' Party, said Verhofstadt "can't claim he wasn't aware of the existence of this [Bermuda-based] company."

"The activities of Exmar Offshore Ltd. were in the consolidated accounts and he received €60,000 as director to know this."

Verhofstadt's spokesperson Bram Delen said: "This is fake news in the purest sense of the word. Exmar Offshore engages in activities that are literally 'off the coast,' such as platforms in the sea, which has nothing at all to do with offshore in the fiscal sense of the word.

"The PvdA [Workers' Party] deliberately creates confusion on the basis of misleading definitions. On top of that, Verhofstadt has left the board of the company more than a year ago."

This article was updated with reaction from Verhofstadt.