SANTIAGO, Chile (Reuters) -- A Chilean judge has questioned former dictator Augusto Pinochet about secret U.S. bank accounts worth up to $8 million, a member of Pinochet's legal defense said on Friday.

It was the first time Pinochet, 88, has appeared before a judge since the Supreme Court ruled in 2001 he was mentally incompetent to stand trial in a landmark human rights case.

"Yes, he was questioned," an aide told reporters, asking his name be withheld.

While Pinochet has long been accused of human rights abuses, the discovery of the U.S. accounts prompted the first accusations of corruption. Pinochet's family and lawyers have denied he stole public monies.

The aide said Pinochet volunteered to testify and was not ordered by the court to do so. The questioning took place in Pinochet's mansion in Santiago about 10 days ago.

Normally, courts would first have to rule to lift Pinochet's immunity as a former head of state before calling him in for questioning.

Human rights lawyers said the questioning demonstrated that Pinochet was healthy enough to stand trial. Court-ordered medical exams say he suffers a mild form of dementia caused by minor strokes.

"Nobody can argue anymore he is crazy or demented. ... It's been proven he is legally competent to face a trial," said human rights lawyer Eduardo Contreras.

A U.S. Senate investigation into the Washington D.C.-based Riggs Bank revealed in July that Pinochet and his wife held up to $8 million in the bank between 1994 and 2002 and cashed several checks in Chile drawn on those accounts.

The former strongman, who ruled Chile from 1973 to 1990, faces hundreds of criminal suits filed by victims' families for murder, disappearances and torture during his anti-communist purges.

With the discovery of the Riggs account, the courts have assigned a special judge, Sergio Munoz, to investigate possible financial crimes as well.

Munoz has already questioned Pinochet's wife and five children and has obtained records from Chile's tax service, stock brokerages, Congress and the military.

Local electronic newspaper El Mostrador reported that tax authorities have found what they believe is a $6 million gap between Pinochet's declared income and the value of his properties and other assets.

But Pinochet's lawyer said the report was inaccurate.

"I believe they got the facts wrong. ... We have always said and continue to say that all General Pinochet's funds are absolutely legitimate," said lawyer Pablo Rodriguez.

Copyright 2004 Reuters.