A former Riggs Bank senior vice president and his wife have been arrested on fraud, conspiracy and money laundering charges related to accounts at the bank of Equatorial Guinea, its largest customer.

Simon Kareri, who was in charge of the Equatorial Guinea accounts, and his wife, Nene Fall Kareri, were arrested by FBI agents at their home in Silver Spring, Md., Channing Phillips, a spokesman for the U.S. attorney's office for the District of Columbia, said Friday.

The two were being arraigned Friday in federal court in Washington, making them the first individuals charged in the Riggs Bank money laundering scandal.

The bank, now owned by PNC Financial Services Group Inc. (PNC), pleaded guilty in January to a felony charge of failing to report suspicious transactions involving foreigners -- including former Chilean dictator Augusto Pinochet and members of his family. Riggs also agreed to pay a $16 million fine, said to be the largest criminal penalty of that type ever imposed on a bank the size of Riggs, a midsize institution with some $6.4 billion in assets. It came atop a record $25 million civil fine levied by a Treasury Department agency a year ago.

Simon Kareri, 47, whose title was senior vice president and senior international banking manager, became the subject of a federal grand jury investigation last summer. At a Senate hearing in July he invoked his Fifth Amendment privilege against self-incrimination and refused to answer questions on the bank's handling of the Equatorial Guinea accounts.

The oil-rich but poor West African country became Riggs' biggest customer with some $700 million in accounts. In one case, Senate investigators found payments totaling $445,800 from a big U.S. oil company into the account of a 14-year-old relative of Equatorial Guinea's president, earmarked for renting office space.