Federal agents raided the home of Ferdinand Marcos' son-in-law and seized artwork and antiques believed looted by the ousted dictator before he fled from the Philippines, a federal prosecutor said.

Armed with a search warrant, about 50 agents from the FBI, Customs and Internal Revenue Service combed the large home in the San Francisco suburb of Woodside, Calif., of Gregorio Araneta III, business manager of the Marcos family and husband of the youngest Marcos daughter, Irene.They came away with a vanload of paintings, sculptures and antiques, Assistant U.S. Attorney Charles Burch said Tuesday, adding they may have been part of a collection purchased by Marcos through intermediaries from New York philanthropist Leslie Samuel in 1981. The collection has been valued at about $6 million, and some sources have said it was among the family's ill-gotten gains.

Araneta, 40, was a land developer during the Marcos regime. Marcos' wife, Imelda, spent an estimated $1.3 million on her daughter's wedding.

The search warrant listed 18 specific items, and the Los Angeles Times reported that some of the information sought in the raid could be important in an investigation being conducted in Hawaii into allegations that Marcos has tried to destabilize the government of his successor, President Corazon Aquino.

In a separate investigation, the U.S. Attorney's Office in New York is looking into allegations that Marcos concealed the true ownership of his artwork and real estate holdings in New York.

The Times reported earlier this week that pressure is mounting within the State Department and Justice Department to indict Marcos and that the deposed leader will be offered a plea bargain that could keep him out of jail but require that he give up the millions in assets he is believed to have smuggled out of the Philippines.

The Aquino government is trying to get the assets back.