SEOUL, South Korea (AP) _ Two gold medal-winning U.S. Olympic swimmers and a third American were detained by police for seven hours today and accused of stealing a marble lion's head from a hotel, police said.

Police officials said swimmers Doug Gjertsen of Atlanta and Troy Dalbey of San Jose, Calif., may face charges resulting from an investigation of aggravated theft. The swimmers each won two gold medals this week.

A third American, identified as swimming coach Ernest Magwni, was also being investigated, police said. U.S. Olympic officials said the man was not a member of the U.S. Olympic delegation. His relation to the detained swimmers was not clear.

Police, speaking on condition of anonymity, said the three were detained in the city's Itaewon District before dawn today after allegedly removing a lion's head decoration worth $830 from the Hyatt Hotel. The three were carrying it around the streets, police said.

The U.S. Olympic Committee issued a statement saying the swimmers had been confined to the Athletes Village while the committee looks into the matter. A statement said ''appropriate action would be taken.''

Chief U.S. swimming coach Richard Quick said the swimmers could be sent home or face other disciplinary action if the complaint was substantiated.

Quick said the charges had been dropped, but Seoul police said they were still investigating and the case was open. The three might be summoned for further questioning Tuesday, a senior officer said.

The three Americans were detained by police on a complaint from the hotel and were taken to the Itaewon police post and questioned for three hours, police officials said.

They were then taken to Yongsan police station and held for four hours before being released into the custody of a U.S. diplomat, who signed a guarantee that they would return for questioning, the police said.

The Korean Broadcasting System (KBS), the state-run television network, reported that the diplomat gained the Americans' release by claiming the swimmers were competing today.

But Gjertsen and Dalbey are not scheduled to take part in any more events, according to Quick.

Jack Sears, the U.S. Embassy's press attache, said he could not discuss the case.

Just hours before the incident, Dalbey swam the second leg of the 400-meter freestyle relay final, which the U.S. team won in world-record time. Gjertsen swam a leg in the 400 freestyle relay preliminaries and thus also gets a gold medal.

Both Gjertsen and Dalbey earlier won gold medals in the world record- setting 800-meter freestyle relay.

Gjertsen, 21, swims for the University of Texas. He was the NCAA 200-meter freestyle champion for the last two years.

Dalbey, 19, from Brigham Young University, won the 200-meter freestyle at the U.S. Olympic Trials.