Police are believed to be examining CCTV footage which shows a man getting in and out of a car minutes after the last sighting of missing Hull University student Libby Squire.
The footage, obtained by ITV News, appears to show a man sitting with his legs out the driver’s side door of a parked vehicle in Hull, said by the broadcaster to be close to where the philosophy student is thought to have disappeared.
He leaves the car, and a minute and a half later a man then is seen opening the front passenger side door and moving around before getting behind the wheel and driving away.
The clip is said by ITV to be “a central part” of the investigation into the student’s disappearance.
During the footage, thought to run from around a minute past midnight to a few seconds before 12.09am on February 1, a cyclist and car pass the parked vehicle.
It comes as Humberside Police were granted an extra 36 hours to question a a 24-year-old man who was arrested on Wednesday on suspicion of abducting Miss Squires.
The 21-year-old was reported missing from the city in the early hours and an intensive search has been mounted by police and volunteers over the last week.
The address where the man was arrested is about half a mile from Miss Squire’s home.
Officers have said Miss Squire was dropped off in a taxi near her home on Wellesley Avenue at 11.29pm on Thursday January 31 and was seen 10 minutes later on CCTV near a bench on Beverley Road, where a motorist stopped to offer help.
She is believed to have been in this area until about 12.09am on Friday.
Police said the taxi driver and motorist have been spoken to and are not suspects.
Detective Superintendent Matt Hutchinson said hundreds of hours of CCTV footage had been trawled through by police investigators.
He said: “While we currently have a man in custody and proceedings are active, we are unable to provide any further comment in regards to the nature of any footage so not to prejudice any potential further proceedings.
“Our priority remains to find Libby and support her family during this incredibly distressing time. We continue to keep an open mind and would ask anyone who believes they have information that could assist with the investigation to please make contact with police.”
On Wednesday, Miss Squire’s parents Lisa and Russ issued a statement which said: “We’d like to thank everyone who has helped this week in trying to find Libby.
“We have been overwhelmed with people’s kindness and support and it’s been incredible how all her friends, students at the university, and members of the public have joined together to help us look for her.”
Humberside Police said Mr and Mrs Squire, from High Wycombe, Buckinghamshire, had met their daughter’s friends and university staff.
In their statement, the couple said Miss Squire - whose full name is Liberty Anna - has two younger sisters and a younger brother, who all live in High Wycombe.
In a statement released on Friday afternoon, Humberside Police said that the force is “still very much treating her disappearance as a missing person’s inquiry”.
A spokesman also thanked more than 50 volunteers who helped officers searching on Thursday night.