Late pop star Michael Jackson pleaded for propofol hours before he died of an overdose of the drug at age 56, his personal doctor said.

In an audio tape played to jurors on Friday in the physician’s trial, Dr. Conrad Murray is heard telling detectives what he says Jackson said. Murray has been charged with involuntary manslaughter.

"I'd like to have some milk," Michael Jackson pleaded according to Murray. "Please, please give me some," he said the day he died on June 25, 2009, reports People Magazine.

On the tape Murray explains to detectives that Jackson wasn't referring to milk but rather to the anesthetic propofol which has a white color and is administered through an IV.

Murray said Michael Jackson craved for propofol in order to sleep.

Murray was interviewed by detectives two days after the death of Jackson. On the tape played in the trial yesterday, Murray acknowledges that he administered propofol to Jackson almost every night at Jackson's request, according to People.

Prosecutors allege that Murray recklessly gave Jackson excessive levels of the surgical anesthetic propofol, which led to the singer’s death on June 25, 2009. Prosecutors also say the drug was misused as a sleep aid.

Murray has pleaded not guilty to the involuntary manslaughter charge. If convicted, he could face up to four years in prison and the loss of his medical license.

His defense lawyers say that Jackson self-administered eight tablets of the sedative lorazepam on his own and then a lethal dose of propofol while Murray was in the bathroom the day he died.