FORENSIC analysis by technology boffins could give detectives vital clues as to where the deaths of the five women took place.Analysts are today attempting to pinpoint the spot where the mobile phones of the victims were last used.

FORENSIC analysis by technology boffins could give detectives vital clues as to where the deaths of the five women took place.

Analysts are today attempting to pinpoint the spot where the mobile phones of the victims were last used.

None of the phones belonging to any of the women have been recovered so far.

It is understood the phones belonging to the first two women who were killed, Gemma Adams and Tania Nicol, are “off network” or permanently switched off.

Matthew Jackson, a computer forensic investigator, said if the killer took the mobile phones it is possible for police to find the exact location where he pressed the off button or the battery ran out of power.

This could provide vital clues about the killer's movements or potentially where the murders took place.

However Mr Jackson revealed that technology experts face a race against time to get the data they need as mobile phone companies such as Orange, Vodafone and O2 only hold such information for a matter of weeks.

Tania Nicol went missing approaching seven weeks ago on October 30 while Gemma Adams was last seen alive on November 15, just over four weeks ago.

Mr Jackson said: “Analysis can trace the last signal location using the last telecom towers the phones were connected to through to triangulation methods.

“Police will contact the service providers for signal location identity data but it is an incredibly difficult process.”

Mr Jackson said all mobile phones constantly emit signals as they perpetually search for the best available network coverage.

This information is logged on computers by mobile phone companies and can reveal the exact position of phones.

When the signal ceases for any reason it creates a form of data footprint that can be traced by experts.

The man leading the investigation, detective chief superintendent Stewart Gull has said the hunt for useful mobile phone evidence is proving “challenging”.

He said: “We are making some progress in respect of call data but we don't want to be drawn on the exact details.”

Mr Jackson said police would also be keen to get hold of call information held by mobile phone companies which will reveal what calls were made and received by each of the women's phones in the hours leading up to their death.

This could potentially reveal the phone number of the killer if it is stored on their phone or they had received a call from him at any stage.

The analysis of phone data for all five victims is part of a huge scientific effort.

Police are reviewing hours of closed-circuit television footage from across southern Suffolk and parts of Essex, to piece together the last movements of the women.