Some of the documents relate to Michael Jackson's 2004 trial
The FBI has released more than 300 pages of formerly classified documents relating to pop icon Michael Jackson.
They include information regarding the singer's 1993 and 2004 child molestation cases, as well as an extortion case where he was a victim.
Despite an application under the US Freedom of Information Act, just over half of the file will stay secret.
The pages do not provide any new information on Jackson's sudden death in June, aged 50.
One document reveals that in 2004, local police in Santa Maria requested FBI involvement believing the court proceedings against the pop star were a "soft target for terrorism" due to the global media coverage.
"No intelligence indicating a terrorist threat" existed, the FBI said, although the bureau did provide other technical and investigative assistance into the case.
In June 2005, Jackson was found not guilty of all charges at the end of the four-month trial.
The documents were released through a Freedom of Information Act request from The Associated Press news agency and other media.
They show that the FBI assisted local authorities on several occasions from 1993 to 2005.
The FBI's legal office in London helped with the child molestation probe in 1993 and in 1995 US customs officials asked the FBI to analyse a VHS videotape as part of a child pornography investigation.
The tape - "a multi-generation copy of poor quality" - was marked in part "Michael Jackson's Neverland Favourites, An All Boy Anthology", the FBI documents say.
In 1993 police in Los Angeles began investigating allegations of child abuse against Michael Jackson made by the father of 13-year old Jordie Chandler.
Jackson vehemently denied the claims and he was never charged. A civil case was settled out of court in early 1994 when he paid Jordie Chandler a reported $20m (£14m).