Thames Water has been blasted for continually disrupting residents by carrying out “pointless” works on Marylebone Road after digging up sections of the busy street nine times in just over a year.

Last weekend marked the latest instance in the debacle which has seen Thames Water frequently attempt unsuccessfully to find a leak into Baker Street underground station.

Two lanes were shut westbound for hours before the water company realised it had dug up the wrong place. Only last month the entire road was shut eastbound for 24 hours when a Thames Water main burst.

The water company says identifying the leaks is not an “exact science”, but Transport for London bosses have rubbished their excuses and argue “unnecessary delays” have been caused for tens of thousands of people.

The recent problems saw two lanes shut from 10pm on Saturday until 2pm on Sunday as long queues of traffic built up with the road reduced to a single lane.

When Thames Water discovered their excavation work was being carried out in the wrong place in the early hours of Sunday morning, it then took nine further hours to completely re-open the road, says TfL.

The London transport body says Thames Water’s lack of planning shows a “disregard for the effect” of its actions. It claims the water company has failed to get its contractors to the site as soon as repairs were completed on three occasions. This has resulted in sections of Marylebone Road sitting idle when the route could have been fully opened to traffic.

Leon Daniels, TfL managing director of surface transport, said: “The tens of thousands of Londoners who have been inconvenienced by these repeatedly pointless works will rightly be exasperated.

“We have had another busy summer Sunday with long delays, whilst the problem with the leaking water main remains unsolved.”

He says he has demanded an explanation from Thames Water and will apply pressure to ensure any further disruption is limited.

A Thames Water spokeswoman said the company will be carrying out further investigations with TfL and London Underground to find the source of the problem.

“Pin-pointing an underground leak is often a lot easier said than done, and we are sorry for the disruption,” she said. “This work was brought forward on the request of TfL – it had been scheduled to take place in two weeks to allow for further tests to take place. We completed the work in the agreed area, however no leak was found.”