Avelino Guillen, prosecuting, has said he is seeking an eight-year jail term for the former president, as well as $661,000 in damages.

Montesinos, who is also serving a jail term, himself faces charges of corruption, drug trafficking, and selling arms to left-wing guerrillas in Colombia.

Fujimori won widespread public support during his presidency for his crackdown on fighters from Tupac Amaru and the Shining Path.

But his administration fell apart after video emerged which showed Montesinos paying bribes to politicians and businessmen.

Cesar Nakazaki, Fujimori's defence lawyer, said his client would plead not guilty.

"Fujimori is innocent … We are going to fight for his acquittal," Nakazaki said.

Possible pardon

Fujimori was sentenced in April to 25 years in prison after he was found guilty of permitting the operations of an army death squad that killed 25 civilians in 1991 and 1992.

He was also found guilty of ordering the kidnap of a businessman and a journalist in 1992.

The corruption case comes weeks after an opinion poll showed that Keiko Fujimori, the former president's daughter, is the leading candidate in the run-up to presidential elections set to take place in 2011.

She has said that she would pardon her father if elected, although it is not clear if she would have the constitutional authority to do so.