A pocket watch worth up to £20,000 that was given as a gift by former US president Woodrow Wilson has been stolen from a London antiques dealer.

The 14-carat gold timepiece was taken from a shop in Pierrepont Arcade, Islington, at around 12.30 pm on Saturday by a man who pretended he wanted to buy a vase.

His payment was declined and, as the sales assistant returned the vase to its display, he opened a cabinet and snatched the watch.

Police are now trying to track the thief down and have released pictures of the watch, which features the seal of the US president on the front of its case.

On the back, an engraved message reads: "From the president of the United States for Charles J Lawrenson, master of the British steamship Nubian.

It adds that the gift was presented to the captain "in recognition of his humane services in effecting the rescue at sea on March 7, 1914, of the master and crew of the American schooner Julia A Trubee".

The owners of the watch are "very distressed" at its theft, said PC Joshua Brown, from Central North Basic Command Unit.

He added: "The item had been in their family for a long time and I would urge the person who stole it to return it as soon as possible."