Detectives trying to unravel the mystery of the identity of the body of a woman discovered in a Norwich lake - and what happened to her - have today issued a plea for people living in the area to send them any private CCTV they have which might have captured the woman on it.

Police believe the public hold the key and have released details about the woman, who was found floating face down in a lake at the University of East Anglia (UEA) in a bid to try and find out who she is.

Officers have revealed the woman, believed to be aged in her late 30s to early 40s, had short dark brown hair with a natural wave, which shows signs of being dyed auburn/dark red. The woman is 5ft 7 and of slim build.

The woman's body, which was clothed in day wear, was found by an angler at in the UEA Broad at about 8.40am on Thursday and was recovered from the water shortly before 9.30am.

A Home Office post-mortem examination has been carried out but has proved inconclusive with toxicology tests now being carried out to try and establish the cause of death which is currently being treated by police as 'unexplained'.

Detective Chief Inspector Dennis Lacey said officers were examining local CCTV cameras, including footage from a camera positioned near to the lake, but also wanted to hear from anyone who might have private camera footage which might have captured the woman.

He said: 'We've got an awful lot of CCTV to go through. It's not the only CCTV on the campus and we're not restricting ourselves to just the campus. 'We're asking if you have got private CCTV if you could view it for us to see if the person matching the description of the person walks by. We've already had a couple of calls from people that have private CCTV and will be going to see them. We know that there's CCTV out there it's just that appeal for people to come forward.

'We're also asking anyone that regularly uses the lake - whether walking, running or fishing - whether they saw anyone matching that description, we would like to talk to them as well.'

Det Chf Insp Lacey, who is leading the inquiry, said police are also working with the university to contact students who lived in accommodation near to the lake to see if they have any information about anyone matching the woman's description too.

He said: 'Efforts to identify the woman have so far been unsuccessful. We've carried out forensic enquiries and these have failed to reveal the woman's identity.

'A preliminary search of the lake area was carried out yesterday and nothing, including personal belongings, was recovered which could assist with the case.

'We hope that by releasing details of the woman's description someone will come forward with information. I would also ask anyone who is concerned about a friend or relative who may not have been seen or heard from recently who matches this description to get in touch with police.'

The description was so similar to that of Norwich woman Emma Belka, 36, who went missing in May before returning home a few days later, that it prompted a visit to her house by officers to check she was okay.

Det Chf Insp Lacey said: 'That was one of our lines of inquiry. We went and saw her and she was alive and well.'

Police have confirmed the incident is not linked to any known missing people cases in Norfolk, Suffolk and Cambridgeshire and inquiries are now being made nationally with the missing person database.

UEA officials have also carried out checks as far as they are able to and have accounted for staff, students and visitors on summer schools and conferences. Officials are also not aware of anyone reported missing.

But regardless of who the person is, have been urged to fly their flag at half mast as a mark of respect.

The university received a message from @Lemel_p who tweeted 'regardless of whether the person found is a student or staff member shouldn't the flag be at half mast today?'

A spokesman for the UEA has confirmed the request is being 'considered' but they are awaiting more details from the police before deciding when might be appropriate.

A number of former UEA students have taken to Twitter to express their shock at yesterday's discovery, including @ryandebruin who tweeted: 'WTF? Body found at the lake I lived opposite last year?' and @emma_thompson10 who wrote: 'Can't believe a bodies been found in the lake outside my flat from last year.'

Meanwhile the UEA has said it is 'continuing to assist the police' with their inquiries following the discovery of a body in the Broad.

Anyone with information should contact Norwich CID on 101.