Whitney Houston was the subject of an extortion plot at the height of her fame when a woman threatened to reveal secrets about her love life, FBI records reveal.

The late 'I Will Always Love You' singer - who died aged 48 as a result of accidental drowning and the "effects of atherosclerotic heart disease and cocaine use" in February 2012 - was the subject of an alleged extortion plot at the height of her fame when the unnamed blackmailer threatened to reveal "intimate details" about her personal life unless she was paid $100,000, according to files released by the Federal Bureau of Investigation (FBI).

The 128 page record, made public after a freedom of information request, reveals that Whitney and her father John Houston received a letter from a Chicago-based lawyer in November 1992 stating that his client planned to "reveal certain details of [Whitney's] private life ... to several publications" unless paid off. The figure was later upped to $250,000.

Whitney contacted the FBI and when questioned, the lawyer told a federal agent that his client "has knowledge of intimate details regarding Whitney Houston's romantic relationships, and will go public with the information" if the demands weren't met.

When later meeting with an FBI agent herself, Whitney claimed her blackmailer was "a friend ... [who] would never do anything to embarrass her".

It appears the extortion attempt was successful as the records show an unsubstantiated amount of money was paid to the woman, who signed a confidentiality agreement that was also found among the records.

The documents, which cover 11 years of federal investigations regarding the singer between 1988 and 1999, also chronicle threatening letters from obsessive fans.