Dr Conrad Murray has launched an appeal against his conviction for involuntary manslaughter.
The medic was found guilty of contributing to the death of pop singer Michael Jackson - was passed away from acute Propofol intoxication in June 2009 - and is currently serving a four-year sentence in a Californian jail.
However, his legal team filed a new motion in California yesterday, asking the appeals court to order a test of the Propofol bottle to check for the presence of lidocaine, a diluent drug commonly mixed with the anaesthetic by doctors to ease the patient's pain.
The defence team feel that if there is no trace of lidocaine in the vial, evidence will suggest the Michael had injected himself with the deadly substance, which they believe would destroy the prosecution's theory that Dr Murray had rigged up a Propofol intravenous drip then left Michael's room.
The request to test the Propofol bottle was twice denied during the doctor's trial.
Dr Murray has previously complained of the conditions at the jail where he is being held, claiming he only had outdoor access once a week, and was suffering constant headaches.
Dr Murray's lawyer, Valeria Wass, has said: "He told me, 'I may not make it out of here alive. This is a very dangerous place. I'm in here dying. The system is intent on killing me'."
Meanwhile, the Executive Director of Consumer Affairs at the California Medical Board has filed a request to strip Michael's former dermatologist, Arnold Klein, of his licence to practice medicine.
Linda Whitney, who has filed the claim, says Arnold has refused to undergo mandatory mental and physical examinations, in direct violation of the Board's orders.
This follows an investigation into an anonymous complaint against the doctor back in 2010.
His representative told TMZ.com: "We're willing to co-operate, we just want to know the reasons behind the investigation. We're optimistic the court will be fair in the matter."