A Drug Enforcement Administration informant may be responsible for turning over the taped jailhouse telephone conversations of deposed Panamanian leader Manuel Noriega to the Cable News Network.

The FBI probe into the leak is focusing on Jose Blandon, a political opponent of Noriega's who may be called upon to testify against the deposed dictator, The Miami Herald reported Saturday, citing anonymous sources.Broadcast of the tapes last month by the network, including one that contained conversations between Noriega and his attorney's office, triggered a court battle over CNN's right to publish versus Noriega's right to a fair trial.

U.S. District Judge William Hoeveler determined there was nothing in the tapes that if published would jeopardize Noriega's right to a fair trial and transcripts of the tapes were released Thursday.

CNN has refused to say how its reporter in Panama obtained the tapes. Prison officials as a matter of policy record the telephone conversations of all inmates, except those between the prisoner and his attorneys which are protected by attorney-client privilege.

Since his incarceration in the Metropolitan Correctional Center near Miami in January following his surrender to U.S. military forces in Panama, Noriega has spent up to 10 hours a day on the telephone.

Between Feb. 1 and Nov. 8, Noriega made some 1,400 calls, the newspaper reported.

The Drug Enforcement Administration subpoenaed 162 tapes in its efforts to obtain more evidence against Noriega and asked Blandon, whose testimoney to a Miami federal grand jury helped obtain the 1988 drug-trafficking indictment against Noriega, to review 22 of the tapes.

The deposed dictators conversations were filled with code words that the DEA hoped Blandon could help crack.

"He was asked to listen to the tapes," a source said. "He also would know the code words Noriega was using."