Red-faced town hall bosses have issued a public apology after residents’ personal details were accidentally published online.

Wandsworth Council blamed the blunder on a “temporary glitch” in an automated electoral roll registration system which resulted in an undisclosed number of personal details being sold to a third-party company.

The information leak was revealed when one of Tooting MP Sadiq Khan’s constituents noticed his family’s details appear on 192.com, which lists names, addresses, age guides and various other information about people and businesses.

Having already requested his details not be passed on to firms via the edited electoral register, the furious constituent - who asked to remain anonymous - contacted his MP and the Information Commissioner’s Office to report a breach of the Data Protection Act, 1998.

Under the Representation of the People (Amendment) Regulations 2002, residents are given the opportunity to opt out of being included on the edited register, which can be bought by companies and used for commercial purposes.

On this occasion, it emerged a telephone re-registration facility run by an external provider to compile the 2008 edited register malfunctioned, meaning people opting out of the edited register were included and those opting in were excluded.

Mr Khan admitted he was worried “the mishandling of personal information occurred in the first place”.

He said: “Personal data must be respected, and handled appropriately. In is not unreasonable for a local resident to expect the council to honour the confidentiality entrusted in them.”

The Wandsworth Guardian quizzed the council last week after the breach was finally exposed.

A council spokesman said: “This was an unfortunate error that arose because of a temporary glitch in the computer software used by our contractor to compile the register. We would like to offer our sincere apologies for what happened.

“As soon as we were made aware of this problem we took immediate steps to rectify it.

"We made sure that the register was 100 per cent correct and contacted 192.com to make sure that no information was displayed on their website that shouldn’t have been.

"We have also introduced a whole raft of additional checks to ensure this problem cannot happen again.

“We also co-operated fully with the Information Commissioner's investigation into this matter.

"The commissioner has since confirmed that he will not be taking any regulatory action against us because he is satisfied with the prompt and effective action we have taken and also because of our very good record on data protection issues.”

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