MIAMI (AP) _ The Cuban-born bishop who helped bring about the release Sunday of the hostages held by Cuban inmates in Oakdale, La., has earned the respect of the exile community here for his defense of refugee rights.

Auxiliary Bishop Agustin Roman was expelled from his homeland in 1961 by the communist government, and has long denounced the imprisonment of Cubans who came to the United States in the Mariel boatlift of 1980.

Last year, Roman and Houston Bishop Enrique San Pedro issued a statement calling for an end to the ''indiscriminate'' and ''indefinite'' jailing of Cubans.

The statement said many prisoners had sent them letters ''full of suffering.''

When the immigration accord between the United States and Cuba was announced, Roman vowed to fight the agreement, which would deport many Mariel felons who have already served their sentences in this country.

Roman flew to Oakdale early Saturday, but was not allowed to talk to the prisoners in person that day. He did record a videotaped message urging the 950 inmates to release the 26 hostages held there since Nov. 2. The tape was shown on closed-circuit television sets around the perimeter of the detention center.

Roman indicated in the message that he had reviewed an agreement reached earlier between inmates and federal agents and deemed it ''honorable,'' said Mark Sheehan, a U.S. Justice Department spokesman.

On Sunday, Roman rode in an open van inside the detention center and blessed the inmates, some of whom wept or shouted ''God bless you 3/8'' A lawyer who advises Roman said his visit was instrumental in the resolution of the crisis later Sunday.

The role of defender of refugees has been a familiar one for Roman, who excludes himself from partisan politics but sees no conflict in being a religious man in a political arena.

''There is no conflict when human rights are involved,'' Roman has said. ''To defend the rights of man is all right.''

For years, Roman has forwarded nearly 1,000 names of political prisoners in Cuba to the U.S. Catholic Conference in Washington, D.C.

He also has worked for Cuban exiles abroad as co-director of the Fund for Aid to the Cuban Exodus, a group that helps needy Cuban exile families.

When Roman was expelled from his homeland along with 131 other priests, he went to Temuco, Chile. He remained there for five years, but came to Miami in 1966 after being drawn by the needs of the exile community.