By Evanna Holland and Jenness Mitchell

The family of a 90-year-old man who has been missing for three days are distraught over his disappearance and have made an emotional appeal for his safe return.

William Scott was last seen in a Greggs bakery in Leith, Edinburgh, at around 4pm on Tuesday.

The great-grandfather and grandfather-of-five was reported missing at 7pm the same day after he failed to return to his home in Chesser.

Mr Scott, who is in poor health and has mild dementia, was described as someone who "brings light into everyone's lives" with his singing and big heart.

His granddaughter, Charlotte Gibson, told STV News: "My grandpa's a very caring and thoughtful person who's the type at 90-years-old he'll still go round his neighbours and see who needs milk and bread and offer to clean their windows.

"He's very active and he's got a big heart.

"It's been hard for the family. We have a small but close family, and he's very much the centre of it.

"There's five grandchildren that have their Christmas cards for him and things, and are starting to wonder a wee bit now about 'where's grandpa' and when are we going to see him again."

Mr Scott's disappearance has been described as out-of-character. He normally follows a daily routine and enjoys the company of friends.

Ms Gibson added: "Every morning he goes to the shops for his newspaper, he always goes to Greggs for a pie and that kind of thing - just the simple things that makes his life enjoyable day-to-day.

"He's a very social person and he's also very cheery. He'll talk to everyone on the bus and he likes to make sure everyone is okay.

"He's a big Leith fan - he likes the history that goes with it.

"He's known to go around different social clubs for his age group and enjoy doing things with other people that he might have known when he was a little bit younger."

Ms Gibson appealed directly to her granddad, urging him to get in touch.

She said: "We're all missing you and we'd love to hear from you."

She also urged anyone in the area to check their outhouses and sheds, just in case Mr Scott took refuge from the weather.

Ms Gibson added: "It's been three nights now, and for someone of 90 years of age who's 5ft, tiny little thing, it's not ideal for him to be out in this.

"The snow is coming this weekend, it's dark by 4-4.30pm.

"We need to find him so that he can be safe.

"He brings light into everyone's lives with his singing, his big heart and he's an important person to a lot of people."

Police Scotland released a CCTV image of Mr Scott, who is also known as Billy or Scotty, as part of their investigation.

It showed the pensioner visiting the Foot of the Walk pub in Leith at around 3.45pm on Tuesday.

Chief inspector David Robertson said: "We have had a very positive response from the public who have been sharing our appeals on social media and calling in possible sightings.

"However, sadly none of those sightings have so far turned out to be William.

"I am gravely concerned for William. We have seen freezing temperatures and with snow forecast for the weekend it is imperative that we do everything we can to find him.

"I am increasing the number of officers working on this inquiry and I would urge everyone to keep sharing William's photo and description and please call if you may have seen him at any time since Tuesday afternoon.

"It is still very possible that he has taken shelter from the cold and so if you have not already checked your shed or garage, please do so."

Mr Scott is described as white, 5ft 1in, balding with white hair and a small wound on his head.

He regularly wears glasses and was last seen wearing a navy jacket, grey trousers and a dark-coloured flat cap.

Anyone who may have seen him is asked to call 101.