Dr. Conrad Murray to Challenge Jackson Family Lawsuit, Point Finger at Dr. Arnold Klein

The embattled Dr. Conrad Murray is challenging a lawsuit filed against him by the father of the late Michael Jackson - and asking why another doc isn't a defendant.

Murray is going after Michael's longtime physician and friend, Dr. Arnold Klein, claiming Klein is at least partly to blame for the singer's untimely, June 2009 death.

As such, Murray says, Klein should be named in Joe Jackson's wrongful death lawsuit. MJ's mother and kids also filed suit against AEG, Michael's concert promoter.

Dr. Conrad Murray (left) is putting some of the blame on Dr. Arnie Klein.

Dr. Murray was on AEG's payroll, serving as Michael's personal physician at the time of his death. Conrad faces involuntary manslaughter charges in criminal court.

His legal declaration today comes in response to Joe Jackson's decision not to name Dr. Arnold Klein as one of the physicians allegedly responsible for MJ's death.

Murray claims: "Dr. Klein may have been medicating Michael Jackson up until or even beyond June 18, 2009, less than one week before Michael Jackson's death."

He also suggests he and AEG were protecting Michael from Dr. Klein, who "prescribed or may have over medicated [Jackson] to such point that AEG Live, LLC had to hire Dr. Murray in order to separate Michael Jackson from Arnold Klein."

Moreover, Murray says "AEG Live, LLC read Michael Jackson the proverbial 'riot act' to get him to stop subjecting himself to overmedication by Dr. Arnold Klein."

"The plaintiff [Joe Jackson] does not explain why, given these allegations, Dr. Arnold Klein is not a required party to be added to accord proper relief."

According to TMZ, he may have a point. Dr. Klein shot Michael full of Demerol - 51 injections in a 3-month span, right up until the week of his death.

Klein, on an unrelated note, is also rumored to be the real father of MJ's children Paris and Prince, and recently claimed that Michael Jackson was gay.

Dr. Murray also casts doubt on others who treated Michael, citing stories revealing that seven doctors other than Murray were fueling MJ with meds.

Murray's team also asked the court to toss the lawsuit altogether, claiming Joe Jackson doesn't have the right to file it, as he's not an estate beneficiary.