PANAMA CITY (Reuters) -Ramon Fonseca, who co-founded the now defunct law firm linked to the Panama Papers scandal, died overnight in hospital, his lawyer told Reuters on Thursday morning.

"He had been hospitalized since the start of April," Fonseca's lawyer Guillermina McDonald said in a phone call, without saying for what Fonseca was being treated.

"Because of this he was not able to attend the hearing," McDonald said, referring to a court proceeding that took place at the start of April to evaluate Fonseca's involvement, alongside some twenty other people, in alleged money laundering. A verdict and sentence in the case have yet to handed out.

Fonseca's niece Carolina Fonseca said on X: "His presence and his fascinating theories accompanied us on this platform. Rest in peace, dear uncle, you will always live in our hearts."

McDonald did not share details about the funeral arrangements.

Fonseca's law firm, Mossack Fonseca, entered the spotlight in 2016 after leaked confidential documents exposed accounts housed in tax havens linked to individuals including Argentine president Mauricio Macri, Ukrainian President Volodymyr Zelenskiy, and Argentine football star Lionel Messi.

(Reporting by Elida Moreno, Natalia Sinawski and Valentine Hilaire; Writing by Sarah Morland; Editing by Christina Fincher and Jan Harvey)