BY JAY WEAVER AND ALFONSO CHARDY

A renewed federal investigation launched after Cuban exile militant Luis Posada Carriles sneaked into the country last year posed a serious challenge at first because the FBI's Miami office had destroyed crucial evidence in the fall of 2003.

The evidence was part of a previous investigation of bomb attacks against Cuban tourist sites in 1997. Destroyed documents included Western Union cables and money wire transfers.

The Atlantic Monthly, in an article in its November issue, suggested the FBI destroyed the evidence to shield Posada from criminal prosecution and avoid angering the Cuban exile community where some view him as a patriot.

The FBI confirmed to The Miami Herald that some case records were destroyed but denied there were any irregularities.

Officials portrayed the destruction as a routine administrative procedure after the U.S. attorney's office closed the case in August 2003 because of lack of progress in the investigation.

''We routinely destroy evidence in cases that have been closed,'' said FBI spokeswoman Judy Orihuela, noting the agency needed to make room for other records in its evidence room at the time.

She added that the FBI has been able to rebuild the body of evidence in the Cuba bombing probe, which targets Posada.

Hector Pesquera, who was special agent in charge of the FBI's Miami field office in 2003, said that any suggestion he sought to protect Posada from prosecution was "preposterous.''

Said Pesquera: "That's not the way this office works or any other law enforcement office works for that matter.''

Guy Lewis, who served as the U.S. attorney in Miami during part of the Cuba bombing case, said such a claim was ``B.S.''