But the 18-year-old's mother Diane says many questions remain unanswered and wants the Independent Police Compaints Commission to look into the case.

The inquest this week heard how Sam and friend Elliot Cooper-Carroll, aged 24, spent Friday, October 26, 2007, drinking and smoking cannabis at Elliot's parents' house in Spencer, Stantonbury.

Fifteen empty cans of Stella lager and a half-bottle of whisky were found the next day.

When Mr Cooper-Carroll woke between nine and 10am he saw Sam was not breathing but an ambulance was not called until 1.17pm and after Mr Cooper-Carroll sat watching TV with the body in his room.

The court heard Mr Cooper-Carroll, his mother and her partner tidied up around the body before police arrived.

A post-mortem four days after death found a blood-alcohol level half the legal drink-driving limit and no sign of cannabis use but traces of heroin and codeine. There was also an injury to his head possibly caused by striking a glass tumbler.

Cause of death was given as the combined effect of drugs and alcohol on his breathing.

Recording his verdict the Coroner Mr Rodney Corner said the gap in time between the discovery of Sam's body and calling an ambulance "had caused everyone in the court to wonder".

He added: "Elliot and his family made no determined effort to make sure their friend got the help he needed and they will have to think long about that."

But after Tuesday's hearing Mrs Down said she still wanted answers. She said Sam had previously used cannabis but not heroin and, despite being told by police the death was being treated as suspicious the day he died, it was not until the day before the inquest, almost six months later, the family learnt of the circumstances of his death.

A statement from the paramedic who attended the scene, and read to the court, was apparently not taken until the morning of the inquest.

Sam's wallet, minus the £190 he had in it, was handed in to Stantonbury Campus weeks after his death and collected by Mrs Down. She reported it to police but, she says, they were not interested.

"It had apparently been outside for weeks but was not even wet," she said. "We just want the case re-investigated."

Yesterday a police spokesman said no formal complaint had been received: "We do take complaints about our service seriously and do have a proper process of dealing with them."