The late son of reality TV star Anna Nicole Smith died of a lethal combination of methadone and the antidepressants Zoloft and Lexapro - a cocktail that would have killed him within hours of consumption, a court heard on Monday.

The conclusion by Dr Govinda Raju, who performed the official autopsy on Daniel Smith, confirms the findings of a private doctor who examined the 20-year-old's body after he died on 10 September 2006 in the Bahamas.

On the third day of the inquest into Smith's death, Raju said the young man had five other drugs in his system - including two that medical personnel used in an attempt to revive him after he collapsed while visiting his celebrity mother at a Nassau hospital. The former Playboy playmate herself collapsed and died on 8 February in Florida from an overdose of drugs.

A lawyer for Anna Nicole Smith's former companion and lawyer Howard K. Stern, who was also in the hospital room the day Daniel died, said the drugs he was taking were all for either depression or back pain. Daniel Smith had bruises on his back and shoulders, but Raju said these could have been caused by medics who tried to revive him. Police have said there is no evidence of homicide.

Police believe he arrived in the Bahamas the night before his death and went directly to the hospital where his mother had given birth two days earlier. He spent the night in a room with his mother, Stern and his newborn half-sister Dannielynn before losing consciousness. The testimony in Nassau continues.