A former doctor and close confident of Michael Jackson has denied he recently provided the late star with medication - as it emerges he wrote fake prescriptions for the star's sister Janet Jackson.

Dr. Allen Metzger was Jackson's personal medic on his 1996 HIStory tour, and even filmed the star's nuptials to first wife Debbie Rowe.

But as America's Drug Enforcement Administration help the Los Angeles cops hunt down doctors who could have abused their position to help provide the Thriller hitmaker with prescriptions, Metzger's history of providing the superstar clan with drugs in fictitious names has come to light.

Speaking to TMZ.com, the physician admits he wrote a prescription for Janet Jackson in the name of her then chef Ricardo Macchi. The medication was for diuretics - used to help the patient pass water.

He also confesses to writing a prescription - in Macchi's name again - for a Hepatitis B injection for the Nasty singer, but insists it was a precautionary measure and the singer didn't have the virus at the time.

But Metzger soon came under scrutiny - when Macchi sued him over the fictitious notes, the doctor received a strongly-worded reprimand from the U.S. Medical Board in 2000 accusing him of "fraudulent medical practise" involving an "international entertainer".

Metzger is adamant he used Macchi's name to save Janet Jackson any embarrassment: "I had done this for Janet for her anonymity."

And the doctor has vehemently denied he was medically involved with Michael Jackson in recent years - but refuses to confirm if he provided the star with prescription drugs during his time as his personal physician.

He tells TMZ.com, "I am not at liberty to discuss Michael's medical care. I have not treated him for ages. I have not treated Michael Jackson for many years.

"I have nothing to do with this tragedy with Michael. I have not prescribed any medication in relation to what happened to him."