The poster was deemed offensive by the police

The poster, featuring a scantily-clad woman with handcuffs and the headline "It's a fair cop" offered free advice to people arrested in Sunderland.

It was placed directly opposite the city's main Gillbridge police station.

But it was removed after three days following a complaint by Northumbria Police to billboard owner Maiden.

Lawyers at Peter Thubron & Co, have accused Northumbria police of "failing to see the joke".

But the force said its officers were offended by the hoarding, which cost �400 for a two-week display.

No complaints were made to the Advertising Standards Authority (ASA) about the billboard, which was designed for the law firm by a design consultancy in Newcastle.

Mr Thubron told BBC News: "The police said the poster suggested corruption and was sexist.

Direct approach

"But what we were trying to do, in a humorous way, was to highlight the fact that everyone is entitled to free legal advice if they are taken to a police station.

"We were not told the poster was being taken down, but I suppose Maiden can do what they want as it's their space."

In a statement to BBC News, Northumbria Police said: "A number of police officers, both women and men, and police staff, found the advert offensive, sexist and in bad taste."

Maiden Outdoor Ltd, which owns billboard sites all over the country, agreed it had acted after a direct approach from the police.

The company stressed it had a policy of self-regulation having talked to the police, decided removal was "the best course of action".

Mr Thubron said he planned to place another poster with a "similar theme" at the same site shortly.