Michael Jackson Doc Conrad Murray: Where are the Documents?

Sources tell TMZ Dr. Conrad Murray will ask the judge in the Michael Jackson manslaughter case to delay the preliminary hearing, because prosecutors still have not anted up all the investigative files.

L.A. County District Attorney spokesperson Sandi Gibbons tells TMZ ... her office has turned over approximately 3,100 pages of discovery, including all of the expert medical reports.

Gibbons says, "Everything we have to date, they have." Gibbons says discovery is an "ongoing process," and as material comes in it's forwarded to the defense. Gibbons added the defense would be getting more discovery on Monday.

Gibbons would not say if her office has received the entire LAPD investigative file -- but our sources say the D.A. got it last December.

Dr. Murray's people tell us they still have not received the full LAPD file and everything else that's available. In fact, they think it's "suspicious" that they were initially told there were "hundreds of thousands" of pages of discovery -- something the D.A.'s office says was an error. Murray's team says there is no way they can be ready for a preliminary hearing when they don't know the facts.

Murray's prelim is supposed to start on June 14 ... and Murray will be in court.