By LARRY ROHTER

RIO DE JANEIRO, Nov. 23 - Gen. Augusto Pinochet, the former military dictator of Chile, was arrested Wednesday in Santiago on tax fraud and passport forgery charges arising from secret bank accounts holding millions of dollars that he maintained under false names in the United States and elsewhere.

Since returning to Chile after being freed from detention in Britain in March 2000 on Spanish court accusations of human rights violations and genocide, General Pinochet has twice been formally accused of human rights violations during the 17 years he was in power. But this is the first time he has been charged with other crimes, and lawyers said the likelihood of a trial and conviction was greater on these charges.

"I believe that yes, it is definitely going to be possible to determine the exact origins of Pinochet's multimillion-dollar patrimony," Carmen Hertz, a human rights lawyer who filed one of the original complaints against General Pinochet, told reporters in Santiago, the Chilean capital.

The former dictator, who has heart, circulatory and neurological problems, has thus far eluded trial in the human rights cases on grounds that his health is too fragile. But court-appointed doctors ruled last month that he was capable of standing trial on the tax evasion and related charges, which also include submitting false documents and reports.

General Pinochet's lawyer, Pablo Rodríguez, harshly criticized the arrest order, calling it "shameful" and claiming that his client "is a man who has been persecuted by international Marxism." He also said that he would appeal the most recent medical ruling and that General Pinochet could not afford to post the $23,000 bail required of him because his personal assets had been frozen. He is to be held under house arrest.

United States Senate investigators originally uncovered about $8 million that General Pinochet and his wife had deposited in accounts at Riggs Bank in Washington. But as a result of additional legal inquiries in Chile, official calculations of his personal fortune have now grown to more than $27 million.

"I have always been an honest man," General Pinochet said under questioning last week by the investigative judge handling the case, Carlos Cerda. Officers of the Pinochet Foundation have attributed his wealth to donations and smart investments, but human rights lawyers contend that much of the money came either from kickbacks on arms deals or funds embezzled from the state.

The arrest in the Riggs case follows other recent legal setbacks for General Pinochet, who turns 90 on Friday. Last week, he and Manuel Contreras, his former secret police chief who has now become an adversary and accuser, were jointly questioned in connection with the investigation into a notorious human rights abuse case.

In that episode, 119 opponents of the Pinochet dictatorship disappeared in 1975 after what was described then as an armed confrontation with state security forces. General Pinochet has been stripped of his immunity from prosecution in the case, and human rights lawyers predict that he could be indicted as early as next month.

Under questioning, General Pinochet acknowledged publicly for the first time that Colonel Contreras did not operate independently and without the general's knowledge, as had previously been his response when asked about human rights abuses under his government, which ended in 1990. "I don't remember well, but it seems that he rendered accounts personally to me and also to members of the junta," he said, according to an official transcript of his testimony.

But in the transcript, General Pinochet also argued that he "could only have an indirect responsibility" for the execution, torture, jailing or exile of thousands of his countrymen. "I regret and suffer for these losses, but God will forgive me if I have committed excesses," he said, adding that "I do not believe" that he had done so.