The possibility that Michael Jackson injected himself with a fatal dose of Propofol is highly 'unlikely', a court heard Thursday.

The final witness for the prosecution in the trial against Dr. Conrad Murray for Jackson's involuntary manslaughter concluded his testimony yesterday.

The singer died in June 2009 from what coroners ruled to be acute Propofol intoxication. Murray has denied administering the fatal shot of the drug to Jackson, alleging that the singer may have injected himself with the lethal dose.

Murray's defence also claims that Jackson may have died not from the Propofol, but the excess of the sedative Lorezapam that was also found in his system at the singer's time of death.

Dr. Steven Shafer, who wrote the packaging insert for the powerful anaesthetic Propofol, ruled out the defence's assertion. He said that 'the possibility of a direct self-injection [of Propofol by Jackson] seems extremely unlikely' since Murray claimed he stepped out of the bedroom for only a few minutes.

Shafer also discounted claims that Jackson died from swallowing eight tablets of Lorazepam behind Murray's back. The amount of Lorazepam found in autopsy reports was simply too 'trivial' to lead to death.

Shafer said that Murray may have given Jackson more Propofol than was initially disclosed. The anaesthesiologist told jurors that Jackson had 25 additional milligrams of the drug in his system than the amount Murray reported to the police in June 2009.

Shafer spent much of the rest of his testimony outlining the proper medical administration of Propofol. He also demonstrated how he believed Murray gave Jackson the drug improperly the night of the singer's demise.

During this demonstration Shafer said Murray did not use an automated pump an action that caused the Propofol IV bag to drip a dangerously fast rate.

The defence will call its first witnesses today with an aim to wrap up proceedings by the middle of next week. Murray's legal team plans to call 15 witnesses, including an independent toxicologist who is expected to support their self-inflicted overdose theory.

Murray can face up to four years of prison and the revocation of his medical licence if found guilty.