Mr del Castillo said he was severely beaten and almost died

Mr del Castillo said he had been kidnapped by a paramilitary death squad controlled by Mr Fujimori in 1992.

The same group had tried to assassinate the current Peruvian president, Alan Garcia, Mr del Castillo told a court in the capital, Lima.

Mr Fujimori is on trial for human rights abuses. He denies the charges.

Mr del Castillo said that he had been at Mr Garcia's house on the night of 5 April 1992, when Mr Fujimori closed the country's courts and parliament.

He said the house had come under fire and was surrounded by soldiers looking for Mr Garcia, who was Mr Fujimori's predecessor as president.

Mr del Castillo said that he believed that the soldiers belonged to La Colina, a group of select army intelligence officers that allegedly operated as a death squad in the early 1990s.

'Severely beaten'

He said that he had helped Mr Garcia to escape, but had himself been arrested and detained in a clandestine prison along with other politicians.

Mr del Castillo said he was beaten severely during his detention and almost died.

"They beat me, they threatened me, they threw me on the ground and told me to get on my knees," he told the court.

THE FUJIMORI ERA 1990: Wins a surprise victory at polls 1992: Dissolves Peru's congress with military backing, assuming greater control 1995: Restores congress and overwhelmingly wins a second term 2000: Re-elected for a third term amid allegations of ballot rigging 2000: Flees to Japan after Montesinos scandal breaks 2001-4: Japan refuses repeated attempts to extradite Fujimori 2005: Fujimori arrested on arrival in Chile on Peru's request 2007: Extradited from Chile to Peru

"We entered a cell and led me in bound and with my head covered. At the time I was reported as disappeared, but really I was kidnapped."

Mr del Castillo also showed the court papers he said proved Mr Fujimori had ordered the kidnapping of his political opponents.

"I have an order here... and here is says 'by request of superiors' and I understand that the superior was none other than the accused [Mr Fujimori]," he said.

But he later added he had received no direct testimony that Mr Fujimori had ordered the kidnapping.

Mr Fujimori has denied ordering the kidnappings and saying he had called for opposition politicians to the "immobilized" within their homes.

Mr Fujimori's trial relates to two massacres carried out by La Colina, in which a total of 25 people died.

It is alleged the death squad was under his direct command. He denies this.

He was earlier jailed for six years on separate abuse of power charges.