Politicians have raised concerns about Hertfordshire Constabulary’s vulnerability to cyber crime after its website was breached last week by a hacker supposedly supporting Julian Assange.

Chris White, the police spokesman for the Liberal Democrat opposition group from Hertfordshire County Council, says the public will be worried that the police fell victim to the stunt and need assurances it won’t happen again.

Last week the Safer Neighbourhoods section of the force’s website was hacked and data stolen, which later appeared elsewhere on the web under the title OpFreeAssange.

Police said no residents’ data was stolen in the raid and it is investigating the incident.

Councillor White said: "The public will rightly be very worried that this could have happened at all in an organisation which should by definition by conscious about security and cybercrime.

"I welcome the fact that there is to be an investigation, but it is vital in these cases that any inquiry is independent and the results - as far as practicable - are made public.

"It is too easy for organisations to give themselves a pat on the back in these circumstances and breathe a complacent sigh of relief.

"The public will need assurance that private data has not been stolen or tampered with and that their communications with the police will not be posted on the Internet by misguided Assange supporters.

"They will want to know what precisely is going to be done to make the system safe in future."

Julian Assange is a controversial transparency campaigner currently locked in a stand-off with police after seeking asylum in the Ecuador embassy in London.

Mr Assange fled there earlier this year after losing a legal battle against extradition to Sweden where he is wanted for questioning in relation to sex assault allegations.