Just when you thought it was safe to go snapping... City of London Police prove they still haven't got the memo.

Yesterday, it was the turn of Grant Smith to feel the heavy hand of the law. Smith is a professional photographer. On Monday he was looking for a location on London Wall appropriate to a portrait of one of the architects responsible for the City’s changing skyline. He went to One Aldermanbury Square, where an altercation with a security guard followed.

The security guard asserted that Smith could not take photos of the building. Smith pointed out that the security guard was wrong. The police were called.

Initially, Smith was relieved: on a previous occasion, the intervention of the local police had led to support for Smith and he had been allowed to carry on with his job.

Not this time. According to Smith, four officers arrived, followed by a police van with flashing lights. He was detained, he claims, under Section 44(2) of the Terrorism Act 2000.

This controversial law permits police to stop any individual for the purpose of preventing terrorism. While police officers acting under this section do not require reasonable grounds for a search, they may do so where there are grounds for suspecting the photography is linked to terrorist activity. That said, the Association of Chief Police Officers (ACPO) has in recent months made it clear that photographers are not fair game for random stop and search.

In a strongly worded statement, Chief Constable Andy Trotter, chairman of ACPO's media advisory group stated: "Everyone ... has a right to take photographs and film in public places. Taking photographs ... is not normally cause for suspicion and there are no powers prohibiting the taking of photographs, film or digital images in a public place."

This message appears not to have been passed on to City of London Police, who continue to use s44 in gung ho fashion to hunt down evil photographers, long after other forces have started to adopt a gentler approach to the subject.

Despite Smith explaining to PC374, who took the lead in what followed, that he was taking photos as part of his job, the police were not satisfied. According to Smith, PC374 said: "The very fact you were here at all is the reason we’ve stopped you."

He says he was then restrained forcibly by another officer, PC29, while the first officer went through his pockets, removing his camera and mobile phone. Smith’s description of events suggest the police action was intrusive and intimidatory, with officers cheered by his discomfiture, both mental and physical.

He claims: "PC [374] went through my pannier, flipping through personal notebooks, gingerly peeking in a plastic bag that contained a towel and swimmers, still wet from my earlier swim. He located my wallet, and pulled out my drivers licence with obvious glee. Each time I attempted to move PC29’s grip on my arms became firmer."