WASHINGTON (CNN) -- A long-awaited Justice Department report released Thursday found no link between the Central Intelligence Agency and the trafficking of crack cocaine in the United States.

The exhaustive, 407-page report was prompted by a series of articles by the San Jose Mercury News in 1996. The articles alleged that a San Francisco-based drug ring sold crack cocaine in Los Angeles and funneled profits to CIA-trained Nicaraguan Contra rebels in the 1980's.

The Contras, with some U.S. government support, were attempting to oust the leftist government of Nicaragua at the time.

The Mercury News' drug-trafficking charges against Contra- connected figures prompted suspicion and anger among many black community leaders in Los Angles.

"After interviewing more than 200 people and reviewing more than 40,000 pages of documents, we did not substantiate the main allegations suggested by the San Jose Mercury News articles," said Inspector General Michael Bromwich.

The newspaper series reported that Nicaraguan drug dealers Oscar Danilo Blandon and Norwin Meneses were also leaders of a Contra group directed by the CIA. It also alleged that the Nicaraguans, along with Los Angeles drug dealer Ricky Ross, received special treatment from federal drug investigators because of their CIA connections.

"While some drug traffickers supplying cocaine to Los Angeles drug dealers were Contra supporters, they were investigated and pursued by the Department of Justice," Bromwich concluded.

"These investigations were not always successful, but we did not find that they were obstructed because of claims that these individuals were connected to Contras or the CIA," he said.

The Inspector General's report also rejected the newspaper's suggestions that the Nicaraguans and Ross were the driving force behind the crack explosion in Los Angeles or in the Unites States as a whole.

The report was originally scheduled to be released in December, but was held up by Attorney General Janet Reno. The move raised accusations that she was trying to suppress the report's findings.

Bromwich called such charges "groundless speculations." He attributed the delay to Reno's fears of disclosing information about a current investigation by the Drug Enforcement Agency involving Blandon as an informant.

In a written statement not mentioning Blandon by name, Reno said Thursday she ordered the delay to protect the integrity of "a very important -- though unrelated-- investigation.