A PAIR of disgruntled window cleaners are warning customers to watch out for bogus callers sponging their cash.

Father and son Colin Hancock, 60, and Simon, 28, say thieves posing as window cleaners have collected more than £1,000 of their customers' cash over the last four years in the Plumstead area.

Mr Hancock senior has been doing the cleaning rounds in the area for the last 32 years and his son came on board around seven years ago.

The freelance window cleaners from Dartford have a strong customer base in Plumstead and are warning them not to handover cash to anyone apart from themselves. Mr Hancock junior believes the culprits are two men in their 40s.

He reported the matter to police in 2004 and was told to distribute notes to customers warning them to watch out who they handed cash to.

The culprits vanished following the campaign, but since January they have made an unwelcome return.

Single Mr Hancock junior said: "Goodness knows what else they are doing in the area. They have taken around £1,000 of our customers' money, which is costing them extra dosh.

"I think they may even live in the area. They are very deceptive, and apparently have even pretended to be on the phone to myself or my dad when thieving the money from customers to make themselves look authentic."

A spokesman for Plumstead police said: "We have received an allegation of individuals obtaining money by deception and officers are investigating.

Call PC Matt Williams on 020 8855 1212.