Police divers expected to be at the site for about a week
Officers have been searching a lake nearly eight months after a woman was found stabbed to death in the boot of her car in Hampshire.
Paula Poolton, 40, of Titchfield, Fareham, was found in her Peugeot 206 near Swanwick railway station on 28 October, 11 days after going missing.
Police divers are searching a lake at Burridge, near Fareham, this week.
Mrs Poolton's widower, Ricky, 53, who was arrested in October, was told in March that he faced no charges.
Specialist police divers from Avon and Somerset began the search on Monday and are expected to continue searching until Thursday.
Det Ch Insp Darren O'Callaghan said: "The lake is one of several sites of interest that have been identified during the course of this investigation.
"We are still trying to locate some of Paula's property including her flip flop, car keys and mobile phone, and we would still appeal to anyone who finds any of these items to contact us.
Specialist police divers began a search of the lake on Monday
"Her flip flop is black, her mobile phone is a red Samsung E-900 and the keys are to her Peugeot 206."
The case was featured on the BBC's Crimewatch programme earlier this month in a bid to find rail passengers travelling through Swanwick station on 17 October, the last day that Paula was seen alive.
Nearly 40 people could be seen on the station's CCTV.
Mr O'Callaghan said police had received 25 calls from members of the public as a result of the programme.
They were all due to be interviewed, he said.
Mrs Poolton was also captured on CCTV at Tesco supermarket in Bursledon at 0930 BST on 17 October, wearing a distinctive white coat with black stitching.