The Joanna Yeates murder investigation continues as police consider taking DNA samples from suspects questioned during a similar murder 37-years ago, sources have claimed.

Yeates, 25, went missing on December 17 after sharing Christmas drinks with work colleagues. Her body was discovered on Christmas Day by dog walkers. She had been strangled.

Four weeks after she disappeared from her Bristol flat, police are focussing on similarities between her murder case and that of student teacher Glenis Carruthers.

Carruthers, 20, was strangled to death in 1974 just yards from where Yeates lived in the Clifton area of Bristol.

Carruthers’ killer was never found but detectives undertaking a cold case review of the murder have been liaising closely with officers in the Yeates investigation after identifying a series of similarities in the two cases.

Both women had been strangled, were found fully clothed and had not been sexually assaulted.

They both appeared to have died quickly without putting up a struggle and in both case the victims were found without shoes.

A source close to the investigation told the Telegraph newspaper: “There are a number of startling similarities between the two cases, despite the huge time gap. DNA testing can eliminate people very quickly and so can be very useful in narrowing the scope of the inquiry.”

Sock may hold clue to Joanna Yeates murder

Meanwhile, police have seized the plans to the house where Yeates, who was an architect, lived.

 Detectives are studying the drawings of the Victorian mansion to see if the murderer might have hidden her body somewhere before dumping it.

The building where Yeates lived is split into flats and Yeates’s apartment is believed to be the only one with just one way in and out.

A spokesman for Bristol City Council said: “The documents have been seized and are part of the investigation.”

Jo Yeates killer may have returned to scene

More than 80 detectives are involved in the hunt for Yeates’ killer, which has already cost £1m.

Leading the Yeates investigation is detective chief inspector Phil Jones of Avon and Somerset Police.

He is under intense pressure to find the killer but remains confident the case will be solved.

Former Scotland Yard detective chief inspector Peter Kirkham is also conducting his own review of the hunt and the key areas police need to check.

A review will ensure that the senior investigating officer has a system in place to prioritise all the information coming in since day one.