New CCTV shows a missing Helensburgh man was last seen speaking to a member of the public on the waterfront.
Police are continuing efforts to find Josh Gayton who went missing on April 16 from the town.
The 21-year-old was last seen on CCTV walking alone away from the town centre, towards the footpath on East Clyde Street, near Lomond Street, at 12.46am.
Further examination of CCTV footage has spotted a man matching Josh's description speaking to a member of the public at 12.25am outside Riva restaurant on West Clyde Street.
Police have asked this person to contact them "as a matter of urgency".
Josh was reported missing after concerns were raised when he didn't arrive for work at Faslane.
Extensive enquiries and checks of CCTV have also found two vehicles which may have driven past Josh as he was walking on East Clyde Street, between 12.15am and 12.46am.
The first vehicle appears to be a white or light-coloured Mini. The second is a blue van, similar to a Ford Titanium Connect.
The van may have had red writing on the side and alloy wheels, said officers.
Again, the drivers of either vehicle is asked to contact police on 101.
Josh is described as 5ft 9ins in height, of stocky build, with brown hair and a red/brown beard.
He was last seen wearing a grey Nirvana t-shirt, black trousers, white Nike trainers and a silver chain with a cross.
Police said there would be an increased visible police presence, while Royal Navy personnel will be in the Helensburgh area carrying out searches over the coming days.
Local area commander, Chief Inspector Allan Dickson said: “It is unusual for Josh to not be in touch with anyone and we are concerned about him.
“We have significant resources dedicated to this enquiry and we are urging the public to come forward with any information relating to his whereabouts.
“If you were in the area at the time, please think back. Did you notice anyone matching his description?
"I am particularly keen to speak to anyone who may have dashcam footage showing Josh, or the two vehicles which may have driven past him between 12.15am and 12.46am.
“If anyone has seen Joshua, or has any information as to his whereabouts, please contact police.
"I would also urge people who live in the area to check outbuildings and sheds.”
Chief Inspector Dickson added: “We are working closely with a host of specialist officers in order to maximise our response. You will see increased activity in the area; please do not be alarmed.
“We have adopted a multi-agency approach to this enquiry, assisted by the Royal Navy and Ministry of Defence Police, and searches will be carried out by land, sea and air.
“Anyone with any information can contact any of these officers, or call Police Scotland on 101, quoting incident 0732 of Tuesday, April 16.”
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