Alisa Dmitrijeva, 17.

An inquest into the “tragic and troubling” death of a teenager whose body was found on the Sandringham estate has failed to establish how she died.

But phone records obtained by police have revealed Alisa Dmitrijeva’s last movements and contradicted the evidence given by two key witnesses in the months following her disappearance.

A cyclist and his young son found Alisa’s body on New Year’s Day in 2012 after stopping for a family picnic at remote woodland in Amner.

The 17-year-old, who lived in Wisbech and attended the College of West Anglia in King’s Lynn, had been reported missing in early September.

Alisa was last seen in King’s Lynn, on August 30, 2012 when she was  in the company of two Wisbech men, Robertas Lukosius and Lauras Boiko.

The inquest, held in Lynn on Monday, heard Alisa’s body was badly decomposed and it had not been possible to establish whether she had died at Amner or elsewhere.

A post mortem examination could not establish a cause of death, but evidence suggested the body had been disposed of by a third party, the inquest heard.

There was no sign of major injury, but “subtle mechanisms of death” such as strangulation could not be ruled out, the inquest heard.

Assistant coroner David Osborne said the pathologist’s report suggested Alisa’s body could have been posed at the scene.

Mr Lukosius and Mr Boiko were arrested on suspicioin of murder in September 2012, but were released without charge. Efforts were made to contact both men ahead of the inquest, but they failed to attend.

Police first questioned the pair shortly after Alisa was reported missing.

Mr Lukosius, 34, who owned a Lexus 300, said he had bought cannabis from her more than once.

He told police he and Mr Boiko had been in Lynn with Alisa on August 30, but they had dropped her back at Asda in Wisbech at around midnight.

Mr Boiko, 30, said he met Alisa through his wife’s children and described her as friendly and “almost naive”. He said they were friends and did not have a sexual relationship.

He confirmed they had dropped Alisa back at Asda that night.

Detective constable Jeremy Pitt said a murder enquiry was launched after Alisa’s body was found and the pair were questioned on several occasions.

Both men provided “no comment” answers to a majority of the questions, but phone records revealed inconsistencies in their stories, he told the hearing.

Phone records showed Alisa had been in Lynn just before 9pm on August 30 and CCTV footage confirmed this, DC Pitt said.

Police in Lynn later stopped and searched the Lexus carrying Alisa and the two men at 12.15am.

“That is the very last sighting of Alisa,” DC Pitt said.

The Lexus was  stopped because it was on record as being involved in crime. Officers have photo evidence of the search – carried out after the time the witnesses said they had dropped Alisa in Wisbech, the inquest heard.

Records showed Alisa last used her phone that night in Snettisham beach car park.

Several attempts to contact her were made the following morning. Although she did not answer, it was possible to establish the phone was still in the car park until just before 11am, DC Pitt said.

Later, when Alisa’s phone was disconnected from the network at 11.22am that morning, officers were able to establish that it was in the Amner area, the inquest was told.

DC Pitt said the phone records also showed the men’s phones were in the Snettisham beach car park area at the time.

Two eastern European men visited a Snettisham shop and called a taxi that morning, the inquest heard.

They were driven to the Jet garage in Heacham where they bought fuel and were dropped at Snettisham beach by the taxi at 9.05am, DC Pitt continued.

The men had not been positively identified as Mr Lukosius and Mr Boiko, he said.

The inquest heard there was no evidence of the pair’s phones being in the Amner area.

Officers established that the sat nav in the Lexus had been programmed for Wisbech about ten minutes after Alisa’s phone lost contact with the network in the Amner area. It was not possible to say where the vehicle was at the time.

“The occupants may have got lost and programmed in a random destination to get back to the main road,” DC Pitt said.

A forensic examination of the car found fibres in the boot matched those found on Alisa’s hair and bra.

Another examination – carried out after the car had been sent to scrap – found traces of seeds from crops grown near the woodland site, DC Pitt said, but the evidence had been compromised by the passage of time.

Officers also found a shell alien to the area near Alisa’s body, the inquest heard.

Mr Osborne said it had been a “tragic, sad and troubling case” and recorded a narrative verdict, concluding: “Unfortunately it has not been possible to determine a cause of death or whether Alisa died at the scene. The circumstances in which her body was found indicate third party involvement, that’s to say she was deliberately placed there.”