Peru's former leader Alberto Fujimori has millions of dollars in his bank accounts - far more than he could have earned, an investigation has found.
Mr Fujimori claims he is the victim of political persecution
Mr Fujimori, who fled to Japan in 2000 amid a huge corruption scandal which ended his rule, denies any wrongdoing.
But a Supreme Court judge says the money is a potential proof that he stole large sums of public money.
Peru has already demanded his extradition to try him for ordering the killing of 25 people by an army squad.
But Mr Fujimori has Japanese citizenship and Japan usually does not extradite its nationals.
Prosecutors believe that he diverted donations by Japanese charities into his own bank accounts during his 10 years in office, from 1990 to 2000.
The former president, who claims he is a victim of political persecution, is supposed to have siphoned off the money with the aid of a governmental body managed by members of his family.
Supreme Court Judge Jose Luis Lecaros said there was "a great imbalance" between his earning power and the hundreds of millions of dollars in his foreign and Peruvian bank accounts.
The country is now preparing a second extradition request which will include the new corruption charges and details aimed at backing up earlier accusations.
Fujimori reportedly claims he only owns a house in Lima and some land in the outskirts of the capital, and that in the days of his presidency he earned the equivalent of $600 a month.
But last year, prosecutors said they had traced a $150,000 cheque that showed Mr Fujimori had diverted money from Japanese aid agencies to one of his bank accounts in 1996.