Dozens of Occupy London protesters evicted from a disused office block in the City of London have criticised bailiffs for using what they claim were heavy-handed and irresponsible tactics in clearing the site.

At the start of a week that could see the eviction of the movement's original encampment outside St Paul's Cathedral, about 50 protesters were evicted peacefully from the UBS-owned building on Sun Street, which since November had functioned as an educational hub known as the Bank of Ideas.

Police and enforcement officers then moved to evict squatters from another building in the complex, also owned by a subsidiary of the Swiss banking group, during which observers claim a photographer was punched in the face by a bailiff who then allegedly drove his car towards at least one person and carried another on his bonnet for 50 yards.

The Metropolitan police said a 45-year-old man had been arrested regarding an allegation of assault and criminal damage. Another man, believed to be an activist, was briefly arrested "to prevent a breach of the peace" but quickly released.

Jules Mattsson, the photographer who claims he was punched, told the Guardian the alleged assault was unprovoked. "I went to get a couple of frames of him, and he just hit me." He wrote on Twitter: "I have a right to go about my job covering news without fear of assault."

In video footage apparently taken after the assault is alleged to have taken place, a man said to be the same bailiff is surrounded in his car by protesters who shout at him, hit his windscreen with bottles and attempt to stop him driving away. He then succeeds in moving off with a man apparently still on his bonnet.

One of the protesters, who gave her name only as Anna, said she had hurt her hand when the man drove in her direction. She also claimed that another bailiff had assaulted her. "I'm a photographer; I had one guy smash his fist into my camera. When I wheeled back from that he then … pushed me back by my face." She added: "The way they were acting was utterly irresponsible."

Rossendales, the private provider whose bailiffs were carrying out the eviction, said they had been appointed by the lawyers of Sun Street Properties, the UBS-owned subsidiary that went to court to evict the activists. In a statement, Alan Smith, the company's high court enforcement and commercial services director, said the protesters had been "verbally abusive" towards his staff and the police.

He added: "As one of our officers left the premises to return to his car, a number of protesters pursued him and he was pushed and abused. Naturally he felt concerned for his safety and acted in self-defence. As he left in his car, more protesters attacked his vehicle, causing damage to it, while police officers were present."

UBS declined to comment.

The demise of the Bank of Ideas came as last-minute efforts by church officials to avoid a forcible eviction of the original Occupy protest camp next to St Paul's looked set to be thwarted by the City of London. The cathedral is keen to offer the protesters a symbolic long-term presence at the site, most likely one marquee giving information about the campaign, in exchange for Occupy removing the other 100-odd tents. But the Corporation of London, the local authority that governs the capital's wealthy financial district, says it will not consider such a compromise.

The standoff is a dilemma for St Paul's, which is desperate to avoid scenes of bailiffs and police forcibly removing activists from the camp, which has been in place on the western edge of the cathedral since mid-October.

The camp is set up on land owned partly by the church, but primarily on designated highway space belonging to the corporation. The high court ruled 12 days ago that the entire Occupy camp should be disbanded, with possible eviction moves due later this week.