Twitter has been forced to reveal the identity of one of its users after a local authority obtained a legal order.

South Tyneside Council approached US courts as it claimed "false and defamatory" statements about three councillors were posted on the site, by five different accounts, including one called Mr Monkey.

The council was awarded a legal order, which required the micro-blogging site to hand over the name, address, email address and telephone numbers relating to the accounts.

"The council has a duty of care to protect its employees and as this blog contains damaging claims about council officers, legal action is being taken to identify those responsible," said the council.

David Potts, one of the councillors named in the posts, added: "We have a duty to look after our employees. It is not a case of politicians not wanting to be criticised".

"I don't mind being criticised. I've got a thick skin. But this blog is perverted, sleazy, sick, filthy and is full of sordid lies."

Independent councillor, Ahmed Khan, was notified by an email from Twitter that his personal details had been released to the council. However, Khan denies he is behind the accounts.

"If a council can take this kind of action against one of its own councillors simply because they don't like what I say, what hope is there for freedom of speech or privacy?" he told the Guardian.

"I don't fully understand it [the email from Twitter] but it all relates to my Twitter account and it not only breaches my human rights, but it potentially breaches the human rights of anyone who has ever sent me a message on Twitter.

Twitter has already confirmed it will provide authorities with details of users who have breached super injunctions if "legally required".

"If we're legally required to turn over user information, to the extent that we can, we want to notify the user involved, let them know and let them exercise their rights under their own jurisdiction," said Tony Wang, head of European operations at Twitter.

Wang's revelation cames after Ryan Giggs threatened to take legal action against thousand of web users, including former Britain's Got Talent judge Piers Morgan and DJ Boy Geroge, after they identified him on the micro-blogging site as the Premiership footballer who took out a super injunction to stop details of an extra-marital affair being published. The order that South Tyneside Council obtained, could well pave the way for Giggs' legal action to take place.