LOS ANGELES, Oct 2: An American judge has ordered the FBI to release its file on the late Beatle John Lennon who was targeted by US security services as a counterculture icon, a report said Friday.

Under the order, made Tuesday by a US District Judge Robert Takasugi in Los Angeles, the Federal Bureau of Investigation must unseal the last 10 pages of the 300-page file that history professor Jon Wiener has fought a two-decade battle to access.

The self-described "radical historian" from the University of California, Irvine, first sought access to the file two year after Lennon was gunned down outside his New York apartment in December 1980, the Los Angeles Times said.

But the US government resisted Wiener's attempts to obtain the documents through the US Freedom of Information Act, sparking a long battle in which Wiener won a string of minor victories culminating in Tuesday's ruling.

"The most interesting thing to me is that it shows how (former US president Nixon feared the political power of John Lennon, the political power of rock 'n' roll," Wiener told the Times.

"It also shows the administration's abuse of power," he said referring to already-released parts of the dossier that showed that the FBI had sought to arrest Lennon on drug charges to ensure he was deported.

One 1972 memo revealed that FBI officials, who conceded their case against the musician was "loose," sought to encourage his arrest at the Republican Convention in Miami that year "if at all possible on possession of narcotics charge." -AFP