A teenager who died of a heroin overdose had earlier claimed his sister bullied him into taking the drug, an inquest heard.

Christopher Emery, 17, was found dead at a flat in Burlington, Street, Brighton, last May 25.

An inquest heard his sister Kirsty, 19, told an ambulance crew her brother had been sick after drinking vodka and cola.

But a post-mortem examination revealed no trace of alcohol, two needle marks in his arm and a fatal dose of heroin in his body.

Detective Sergeant Jane Palmer, who investigated the boy's death, told the hearing Kirsty had been interviewed under caution in connection with the alleged manslaughter of her brother.

Ms Palmer said: "The Crown Prosecution Service said there was not enough evidence to proceed with any charge."

Brighton and Hove Coroner Veronica Hamilton-Deeley recorded an open verdict and urged police to reopen their investigation if officers learnt any new information.

She criticised a lack of action after Christopher claimed Kirsty had injected him with heroin against his will.

The inquest heard Christopher, who had been in care since he was four, had been staying with a foster family in Portslade in the months before his death.

The night before he died he had stayed with Kirsty at a friend's flat and the next morning she found him dead.

There was no evidence he used heroin but two months before he died he had alleged Kirsty had bullied him into taking the drug and injected him against his will.

The allegation was reported by his social worker to the police Child Protection Team. But they said action could only be taken if Christopher made a complaint himself against his sister.

After his death a police investigation revealed another teenager claimed Kirsty had injected her against her will two years earlier, the inquest was told.

Statements made to the police by Kirsty, who admitted to officers she was a heroin addict, were read out at the inquest.

She said Christopher had been drinking the night before he died and had not taken any drugs. Ms Palmer said Kirsty denied ever injecting her brother.

Kirsty, of no fixed address, failed to answer a summons to appear at the inquest, along with two friends.

The coroner said she was unhappy about the Child Protection Team's lack of action and would write to the team leader to request an investigation.

She said: "I am quite satisfied Christopher was not dependent on drugs, nor was he even an occasional user of heroin.

"In this case I am unhappy about evidence and I don't think that any of us has the full story."