LA PAZ, Bolivia Former Chilean dictator Augusto Pinochet"s wife and four grown children were arrested Monday in connection with an investigation of more than $20 million held in secret bank accounts linked to the ex-military strongman.

Court officials in Santiago, the Chilean capital, told reporters that Judge Carlos Cerda ordered the arrest of Pinochet"s wife, Lucia Hiriart, and four of the couple"s five children on tax fraud and other charges.

Reuters news service reported that Pinochet"s wife and three of the couple"s children would be detained under house arrest in Santiago, at least until today, but that his eldest son, Augusto, was released on bail. The remaining family members were expected to post bail today.

Last summer, Pinochet"s wife and youngest son, Marco Antonio, were released after being detained on charges of using false passports and other documents in connection with management of the secret accounts.

The case involves about $27 million in foreign bank accounts that have been tied to Pinochet in a corruption case that has outraged even some of his staunchest supporters. Some legal observers in Chile say Pinochet is more likely to be imprisoned for the corruption charges than in the many human rights cases filed against him.

Pinochet has been accused of complicity in about 3,000 deaths and disappearances during his 1973-90 rule.

Representatives of the Pinochet family have proclaimed their innocence. Attorneys for the ailing former dictator have said the money came from legitimate donations.

A 1994 report by U.S. Senate investigators found that the former Riggs Bank in Washington had used shell companies to help Pinochet hide millions in assets from prosecutors while he was under house arrest in Britain on human rights charges. Last year, Riggs, since merged with PNC Bank, agreed to pay $9 million into a fund for victims of the Pinochet dictatorship to settle a case about the bank"s role.

In Chile, the ongoing investigation, with revelations every few months, is known as the "Riggs Case." The ex-dictator, now 90 and in frail health, also faces tax-fraud and human rights charges in Chile but remains free pending appeals. Last week, a judge stripped Pinochet"s immunity in a case involving alleged abuses at Villa Grimaldi, an infamous detention center for suspected leftists during his reign.

Pinochet took power in a bloody military coup that toppled the democratically elected leftist government of Salvador Allende.

A former political prisoner of the Pinochet regime, Michelle Bachelet, will take office this month as Chile"s fourth democratically elected president since Pinochet"s departure.