An expert from the Natural History Museum has been drafted in to help police establish exactly how long the body of a woman on the Queen's Sandringham estate has been there.

Detective Chief Inspector Jes Fry, senior investigating officer with the Norfolk and Suffolk major investigation team, has said the decomposed state of the body has so far hampered efforts to compile a DNA profile of the woman.

Det Ch Insp Fry, speaking at a media briefing at Norfolk Constabulary's Wymondham HQ, said samples were taken from the tooth, femur and muscle of the calf to test for a DNA profile. The first two sets of tests have not yet revealed a usable DNA profile.

He said: 'Our next step is to carry out a different test on the bone, which takes longer. I'm confident we will yield a usable DNA profile shortly.

'When this happens, we will be checking this sample against the DNA database before prioritising potential nominals with our Holmes database to obtain DNA from their possessions or family members.'

Results of the latest test, which involves DNA being extracted from a powder form of the bone, are expected on Monday and if they produce a positive DNA result could lead to the identity being revealed within hours – if the person is on the database.

A specialist from the Natural History Museum visited the site yesterday to carry out further entomological tests – the study of insects and their life span – to try to discover exactly how long the body had been there.

Det Ch Insp Fry, who has between 30 and 35 officers working on the case, said by identifying the pupa casings and larvae of certain insects at the scene experts would be able to establish a 'time frame as to how long it's been there'.

The remains at Sandringham were spotted by a dog walker around 4pm on New Year's Day, about a mile from the main gate to Sandringham House.

Analysis of bone development and other samples have helped detectives identify the body as that of a white woman aged between 15 and 23.

The force has issued a further description of the victim, saying she was between 5ft 4ins and 5ft 6ins tall, with high cheek bones.

Botanists have been consulted who say seasonal growth patterns suggest that the body was not put there earlier than August.

Det Ch Insp Fry said: 'Ivy doesn't grow after August and there's no ivy growing over her and therefore she's not been there before the end of August.'

The site where the body was found is used regularly for pheasant and partridge shoots, often attended by members of the royal household. A pheasant shoot is known to have taken place on December 28.

A Home Office post-mortem was carried out by Dr Nat Cary, and assisted by Dr Julie Roberts, a forensic anthropologist, which established it was 'highly unlikely that death was through natural causes'.

Det Ch Insp Fry said it has not yet been possible to establish how the victim died because of decomposition although the post-mortem has found no evidence of injury through firearms or bladed weapon or other trauma such as broken bones.

He said speculation about the identity of the victim was 'unhelpful', particularly for the families involved.

He added: 'We are in touch with a number of families and are particularly focused on missing persons' cases in Norfolk and neighbouring counties. My job is to remain objective and deal in facts to ensure the right outcome.'

One case the force is looking at is the disappearance of Latvian Alisa Dmitrijeva, 17, from Wisbech, who has not been seen since August.

But Det Ch Insp Fry said the force had been in touch with 'several other families' to inform them of progress.

He added that some articles had been recovered from the area around where the body was found but said they would only be used to try to identify the victim if they failed to get a positive DNA result.

Despite being unable to identify the victim Det Ch Insp Fry said he was pleased with how the investigation was going.

He had 'several officers' making inquiries, including trying to obtain CCTV in the area that might have captured relevant individuals.

'Once we identify who the deceased is then we can look at possible associates or possible movements of that person in vehicles belonging to them, their appearance on CCTV to identify timeframes about movements and that sort of thing,' he added.

Anyone with information should call the Norfolk and Suffolk MIT on 101 or Crimestoppers anonymously on 0800 555 111.