An inquest will open in King's Lynn next month, almost three years after she was last seen alive. A full hearing will be held at a later date.

Alisa, 17, was last seen in the Friars area of King's Lynn, in August 2011 - two years after she moved to Wisbech from Latvia.

Her badly-decomposed remains were found on New Year's Day 2012 on the Royal Estate near Sandringham.

Two men arrested in connection with her death were never charged. Detectives admit forensic tests have not revealed how or when she died.

Det Insp Marie James, of the Norfolk and Suffolk Major Investigation Team, said: 'Despite exhaustive enquiries the decision has been made to pass the case through the Her Majesty's Coroner for an inquest.

'The police investigation into this case will remain open and any new information or leads will be followed up and acted upon.'

Forensic experts took more than a week to identify Alisa's partially-clothed body, which was found on the edge of a shooting covert near the Royal Stud.

The last-known sighting of Alisa, who lived on the Railway Road, in Wisbech, was in Friar's Street, King's Lynn.

She was seen in a green Lexus car with two men in the early hours of Wednesday, August 31, 2011.

Alisa is believed to have spent the night at a beach party at Snettisham, possibly leaving the open-air gathering at some point in the evening and returning later on.

Her death was treated as suspicious. The car was later traced and soil found in the car was found to match samples taken from around the spot where Alisa's remains were found.

Two men, aged 28 and 31, were arrested in May 2012 and released on bail, after being questioned over her death. Four months later, they were formally released from bail without charge.

Alisa was cremated in January 2012, and her ashes taken back to Latvia. They were interred in a cemetery in the Baltic country's capital Riga, where she spent her childhood.

Afterwards, her grandmother Lidija Dmitrijeva, speaking through a translator, she said: 'We are still very upset at the loss of our beautiful daughter, granddaughter and sister Alisa.

'She was a very friendly girl, had very good marks at college and had a lot of friends, but did not use drugs.

'We cannot live without the answers to so many of our questions, questions that not even the police can answer so please can the person who knows what happened to Alisa come forward. I'm worried I won't be alive to see these people punished.

'Please help the police if you have anything to say - we believe someone is too scared to talk, but please speak up, we wait for your news.'

Alisa's family are still waiting. Anyone with information should call Norfolk police, on 101.