A search of a university lake where the body of a woman was discovered has uncovered no further clues to her identity, which remains a mystery.

Divers carried out a fingertip search of the UEA Broad yesterday and found only a mobile phone, which has been ruled out as a line of enquiry following tests.

It's almost a week since the body of the woman, aged in her late 30s/early 40s, was found floating face-down in the water by an angler shortly after 8.30am on Thursday (1 August).

Since then police have released the woman's description and a photograph of the dress she was wearing, in the hope it would prompt calls from the public who may have seen her in the area near to the lake.

Detective Inspector Richard Graveling, from Norwich CID, said that while it was unfortunate that nothing was recovered from the lake which could reveal her identity, officers remained optimistic.

He said: 'While it's disappointing not to find anything which could assist with the inquiry we remain hopeful that someone will come forward with information.

'Cases like this are unusual as you would normally have friends or relatives concerned for the welfare of a loved one coming forward to report them missing, especially now we're almost a week on since she was found.'

The water search began at lunchtime and finished early evening at about 6pm. A mobile phone was recovered from the bottom of the lake but officers have ruled this out as a line of enquiry.

'We've carried out initial tests on the phone and we are satisfied this didn't belong to the woman and almost certainly belonged to a student,' said Det Insp Graveling.

He added officers continued to work on several lines of inquiry following a 'steady' number of calls from the public in response to police appeals.

A Home Office post mortem proved inconclusive and while further tests are being carried out to establish the cause of death, officers believe it's likely the woman drowned in the lake. Police have also confirmed that at this stage there is no evidence to suggest she was the victim of violence or that a third party was involved.

She is described as white, 5ft 7, of slim build with short dark brown/auburn hair and was found wearing a black dress which had a large rose pattern design in peach/cream.

Police are keen to hear from anyone who may have seen a woman fitting this description in or around the lake area within the last couple of weeks.

Anyone with information should contact Norwich CID on 101.