Thames Water is taking up to two months to fix leaking pipes despite claiming an average repair time of five days.

Britain's biggest water supplier is wasting millions of litres of water a day by failing to respond to the public earlier, a BBC investigation found.

Thames is one of seven water companies introducing hosepipe bans from 5 April, blaming drought conditions.

Since being contacted by Watchdog, Thames Water has removed the "five day" claim from its website.

The company admitted its response to leaks "isn't good enough" in some cases.

The BBC's Watchdog programme calculated that a leak from one basement of a central London flat lost up to 130,000 litres in two months.

The home owner, Jeremy Gompertz, reported the leak nine times and described the company's response as "scandalous".

Running water

"It took them three weeks to even come and have a look at the problem," said the 74-year-old barrister, who lives in Islington.

It took them three weeks to even come and have a look at the problem Jeremy Gompertz, Homeowner

"The last time they came, they reported back that they couldn't even find the leak. I can only assume that they went to the wrong premises, as if you stand outside my property you can actually hear the water running.

"I think it's outrageous that when we're threatened with water restrictions because of the drought, they can't be bothered to come and remedy a leak which has been running for two months."

Thames Water disputes that the leak was responsible for all the water coming into the property but admitted not returning calls.

"We apologise unreservedly for that, and also for our slow action on this. There is no excuse and we are taking steps to ensure there are no repeats in the future."

Thames Water Live BBC Watchdog monitored leaks at Thames Water Live from 22nd February 2012

There were 441 "active" leaks, of which 210 were repaired within the next five days

Of those, 48 had not been repaired after 20 days

Watchdog inspected a leak in north London losing 3 litres per minute

The company, which supplies London and the South East, has met leakage-reduction targets laid down by the industry regulator, Ofwat, for the last five years.

It said leakage had been reduced by a third since a peak in 2004, and that it was currently repairing 1,000 leaks a week.

"We fix leaks in order of priority to prevent as much water as possible from being wasted.

"While in the Home Counties it is comparatively easy to dig up a road and repair a broken pipe, doing the same job in busy central London can be a lot trickier.

"However, we recognise that in some cases the speed we fix leaks isn't good enough. We are continually working to improve."