Police have issued a warning after a burglar posing as a “water board” official stole treasured family heirlooms from an elderly woman after tricking his way into her home.

The family of the victim, who is in her 80s, say she was left feeling “violated” and unsafe in her own house after the jewellery theft between 4pm and 4.45pm on Wednesday last week (July 16).

The culprit swiped rings, watches and other items after tricking his way into her house in Brim Hill, Hampstead Garden Suburb, by showing an identification card and saying he needed to check the water pressure.

The suspect was white and in his late 30s or early 40s, smartly dressed in a grey jacket and trousers, and carried a clipboard.

Relatives of the elderly woman, who wished to remain anonymous, joined police in appealing for witnesses and urging other residents to be alert to similar distraction burglary methods.

Her 36-year-old son-in-law said: “It’s something other people need to know about.

“They were family heirlooms, things that have been in the family for generations and generations with huge sentimental value.

“This man preyed on a very vulnerable, elderly woman. I just think he’s heartless and without conscience.”

The woman noticed the jewellery had disappeared after the man’s visit.

Det Ch Insp Gary Randall, of Barnet Police, said: “I would like to warn everybody to be on their guard and not to let anyone who calls unexpectedly into your home, even if they do have an identity pass on them.

“Ask them to return when you are with a family member or friend. A genuine caller will not mind if you do this.”

Anyone with information should contact police on 101 or call Crimestoppers anonymously on 0800 555 111.