The search for a sea kayaker last seen four days ago is continuing.

Dominic Jackson was last seen between 10.30am and 11am on Saturday in the Cullen area of Moray, where he asked locals about the best place to go kayaking.

He is believed to have set off from nearby Portsoy Harbour, where his VW Transporter van was found.

The alarm was raised on Sunday night when the 35-year-old failed to return to his home in Laurencekirk, Aberdeenshire.

A search was launched that evening involving the police, coastguard and RNLI.

Dozens of volunteers have helped in the search, including Mr Jackson's father Dominic and brother Stuart.

Despite warnings from Police Scotland and the RNLI, members of the public returned to comb the coast around Portsoy and Sandend on Wednesday.

"I would like to thank the volunteers who have turned out for their support both yesterday and today - I cannot stress how much it is appreciated and I know it has been a great source of strength for Dominic's family at this difficult time," inspector Kevin Goldie said.

"However, weather conditions are not expected to improve today and as our search operation enters more difficult and challenging terrain, our priority must be your safety.

"I know that a number of volunteers have turned out with kayaks today to assist with the sea search, however given the conditions I would urge you to find other ways of supporting Dominic's family.

"Police Scotland has specially trained staff who we are unable to deploy at this stage due to the deteriorating weather and dangerous conditions; I would advise members of the public also not to put themselves at risk."

"By no means does this mean the search is being scaled down, however we need the right people in the right places at this time," he added.

A kayak believed to belong to Mr Jackson, who had only recently taken up the sport, was found near Wick, Caithness, at 9pm on Monday.

A piece of safety equipment which had been attached to the kayak was discovered at Porknockie, Moray, on Tuesday.

In a statement released on Monday, his family said: "We are desperately worried for Dominic and would urge him to make contact with his family or police to let us know he is OK.

"This is completely out of character and we just want him home.

"We would also like to thank local people who are assisting with the search."