Los Angeles Sheriff Lee Baca, whose department is being investigated for allegedly attempting to cover up Mel Gibson's anti-Semitic rant last week, previously hailed the actor as "a wonderful man".
Gibson, who was arrested for misdemeanour drink-driving, was praised by Baca for his work on the sheriff's charitable foundation in 2002, according to US TV show Extra.
Police were reportedly slow to disclose details of the troubled star's anti-Jewish tirade, and internal investigators are probing whether authorities were keen to conceal Gibson's verbal abuse.
A video from 2002 shows Baca saying: "I'm grateful that, Mel, you are such a wonderful man."