A Tayside Police spokeswoman said the reconstruction would involve three officers and will show Mary and her sister leaving the Gauger Bar in Dundee’s Seagate and making their way to Fat Sam’s nightclub in South Ward Road.

The filming will then concentrate on Mary’s movements after leaving the club in the early hours of Thursday morning where CCTV and witness accounts place her walking with a man, who Tayside Police have since identified, in North Lindsay Street, Bell Street, Irvine’s Square, into Wishart Place and East Marketgait, near to the junction with King Street.

The officer leading the inquiry, Detective Chief Inspector Shaun McKillop, said, “We will be filming in various areas across the city centre in order to produce a visual account of Mary’s movements.

“Not only will this provide us with an essential briefing tool for officers working on the inquiry, we hope that by showing the reconstruction publicly it will trigger something in somebody’s memory.”

Police today were back searching the East Marketgait and King Street areas — where Mary was last seen — conducting inquiries, including searches of residential gardens and reviewing more CCTV footage.

Investigators also moved to the Victoria Road area, searching tenements and back gardens in streets such as Forebank Road and Bonnybank Road.

Officers were also located at the rear of the Wellgate Shopping Centre looking for clues.

DCI McKillop said the identification of the last person known to have seen Mary on the morning of February 25 was a “major breakthrough”.

He said the man, who was pictured in CCTV footage and also in a mobile phone photograph taken at Fat Sam’s, has been assisting with inquiries. The man, who has not been named, is believed to be from the west coast of Scotland.

According to DCI McKillop, he came forward “quite willingly” to assist with the inquiry and has not been arrested in connection with Mary’s disappearance.

Since the mum-of-three went missing, Tayside Police has been pumping all its resources to try to piece together her last known movements.

It has now been described as a “full-scale investigation” with around 50 police officers and support staff now involved in the probe, including dog handlers and CCTV specialists.

Detectives are said to be “seriously concerned” about Mary’s well-being and have already carried out extensive door-to-door inquiries in the Dura Street area, following information received, plus searches around the route Mary was seen to have taken.

Mary was last sighted with the man in Marketgait, near to its junction with King Street, at about 3am on February 25.

The man she was seen with was later spotted in the area of the Shell filling station in Allan Street, East Marketgait, at around 5am the same day.

There was no sighting of Mary at that time.

Mary walks with a limp, is 5ft 2ins tall and has long brown hair and blue eyes.

On the night she disappeared, she was wearing a black and white patterned dress, black leggings, a white duffel coat and flat black shoes.

She was carrying a black handbag and a pink inflatable toy.

DCI McKillop believes Mary may have dropped some of these items on her route, and he has urged people in the area to back gardens and bins for her belongings.

Officers were also spotted at Stobsmuir Ponds, carrying out ground searches.

DCI McKillop added, “We’re interested in the movements of people around Dura Street at about five in the morning on Thursday, February 25.”

Anyone who has any information regarding Mary’s disappearance should get in touch with Tayside Police on 0300 111 2222 or speak to any officer. Information can also be passed on anonymously to Crimestoppers on 0800 555 111.