Ramon Fonseca, one of the founders of Panama's Mossack Fonseca law firm, is seen during a TV interview with Telemetro in April 2016
Ramon Fonseca, one of the founders of Panama's Mossack Fonseca law firm, is seen during a TV interview with Telemetro in April 2016 AFP

Panamanian lawyer Ramon Fonseca, co-founder of the now-defunct law firm at the center of the "Panama Papers" scandal, died while awaiting sentencing in his money-laundering trial, his lawyer said Thursday.

Fonseca died during the night while hospitalized in Panama City, a member of his legal team said, adding that health issues were "why he did not attend the trial" that opened on April 8.

No further details were given about the cause of death of Fonseca, 71, who started the law firm Mossack Fonseca with his German-born colleague Jurgen Mossack.

"Every judicial trial carries an enormous weight for the accused and much more so in the circumstances in which this trial took place," Fonseca's lawyer Daika Indira Levy told AFP after his death was announced.

Leaked documents from Mossack Fonseca in 2016 revealed how many of the world's wealthy stashed assets in offshore companies, triggering scores of investigations around the globe.

Prosecutors had requested a sentence of 12 years in prison for Fonseca and Mossack, whose money-laundering hearings ended on April 19.

The pair were on trial alongside more than two dozen others, mainly former employees. Fonseca did not attend the hearings.

The prosecution accused Mossack and Fonseca of "concealing, covering up and providing false information to banks for the opening of accounts and concealing ownership of assets."

They were also alleged to have "received and transferred funds from illicit activities in Germany and Argentina."

The trove of 11.5 million leaked files implicated influential figures including billionaires, politicians and sports stars.

Icelandic prime minister Sigmundur David Gunnlaugsson was forced to resign after it was revealed his family had offshore accounts.

Then Pakistani prime minister Nawaz Sharif was disqualified from office for life after being implicated in the documents.

Others implicated included former British premier David Cameron, football star Lionel Messi, Argentina's then-president Mauricio Macri and Spanish filmmaker Pedro Almodovar, to name but a few.

Many of those caught up in the scandal put forward reasons to explain their offshore presence and said they did not act illegally.

Even so, Mossack Fonseca said in 2018 that it would close due to "irreparable damage" to its reputation.

The scandal dealt a severe blow to Panama's image as an offshore financial hub.

Former Panamanian president Ricardo Martinelli, who has taken asylum at the Nicaraguan embassy after being sentenced to almost 11 years in prison for money laundering, paid tribute to Fonseca, an ex-classmate.

Martinelli described Fonseca as "a great human being who suffered atrocious persecution."