SAN JOSE, Costa Rica (AP) _ Nicaraguan rebel leader Adolfo Chamorro was deported to the United States on Friday after Costa Rica declared him an undesirable alien, Public Safety Minister Benjamin Piza said.

He said Chamorro, a leader of the U.S.-backed Democratic Revolutionary Alliance, or ARDE, was put on a commercial flight to Miami, where he has been living for some time.

In February 1985, Costa Rica expelled Chamorro for making what this country considered inflammatory statements against the leftist Sandinista regime in neighboring Nicaragua. He was banned from returning to Costa Rica.

Costa Rica allows ARDE to operate a small propaganda office here so long as it remains low key.

Speaking to reporters, Piza denied rumors broadcast by several Costa Rican radio stations that Chamorro was arrested on drug-related or weapons smuggling charges when he tried to re-enter the country Wednesday.

Piza also denied initial reports that Chamorro arrived Wednesday on a commercial flight. He said Chamorro entered the country in a rented twin- engine plane, accompanied by two Cubans and a Costa Rican, who were also arrested.

The minister refused to give details or say what happened to Chamorro's companions.

ARDE is a small rebel group, divided by factional disputes, that operates on in southern Nicaragua. It is not connected with the larger Nicaraguan Democratic Force, based in Honduras, which is active in northern Nicaragua.

The two rebel groups, popularly known as Contras, are supported by the United States.