The mother of a 15-year-old girl who was stabbed more than 30 times by her ex-boyfriend in Waterloo has won her case for a full inquest into her death.

Arsema Dawit was stabbed 32 times by Thomas Nugusse in the lift at her block of flats in Waterloo, central London in June 2008.

In the weeks before the attack, Arsema, her mother Tsehaynesh Medihani and a cousin, complained to the police that Nugusse, 22, had become increasingly obsessed with her and had assaulted and threatened to kill her.

Medihani, has accused police of ignoring her daughter's warnings and that Nugusse was a danger to her daughter.

An Independent Police Complaints Commission (IPCC) report in 2010 found that a receptionist at Kensington had not passed on the relevant information to a senior officer, but also concluded no one at the Metropolitan Police was to blame.

Mr Justice Silber said steps should have been taken by the police to avoid the situation and should be investigated at a full inquest.

Nugusse could not be tried as he suffered brain damage after attempting to hang himself in prison.

In May 2009, an Old Bailey jury could not return a conventional innocent or guilty verdict but instead found that Nugusse had "committed the acts".

Medihani was not happy with the original criminal proceeding or the IPCC report and asked Dr Fiona Wilcox, to hold a full inquest. But in June 2009, Wilcox refused to complete the inquest she had opened.

Silber has now thrown that decision out and ordered a full inquest to be held at a different coroner's court.

Silber said: "There is ample evidence to justify a credible and deeply worrying threat to kill Arsema which showed the coroner was not entitled to conclude that there was not sufficient cause to resume the inquest".

"There were steps that could have been taken and ought to have been taken" - including speaking to Nugesse and assessing what kind of risk he posed, arresting him for assault and offering safety advice to the victim and her family."