A New York police officer whose allegation of assault against an Occupy Wall Street activist could send her to prison for seven years is being sued by another Occupy campaigner, who alleges that the officer injured him on the same day.

Officer Grantley Bovell alleges that Cecily McMillan intentionally elbowed him in the face as he was arresting one of the dozens of protesters from the anti-capitalist movement who were seized at Zuccotti Park in lower Manhattan on 17 March 2012.

McMillan, 25, claims she swung her arm only after Bovell grabbed one of her breasts from behind. She denies a charge of felony assault. Her much-delayed trial, the last in a series of Occupy prosecutions, is due to begin at the state supreme courthouse in Manhattan on Monday.

Bovell, who has faced several previous allegations of wrongdoing, has now been accused in a lawsuit of injuring a protester while removing him from the 17 March demonstration, which marked six months since the start of the Occupy protests. Although McMillan was active in Occupy Wall Street, she says she was only in the park briefly that day, to meet a friend.

The protester, Austin Guest, alleges that Bovell dragged him down the aisle of a bus while “intentionally banging his head on each seat”. His attorneys said in an updated complaint filed to federal court in Manhattan last week that as a result he “suffered physical, psychological and emotional injuries, mental anguish, suffering, humiliation, embarrassment, and other damages”.

They allege that after being put face-down on the ground and tightly handcuffed, Guest, a 33-year-old graduate of Harvard University, was “dragged up the stairs and thrown head-first into the bus”, which was to take him and other protesters to a courthouse for processing.

“He was carried like a battering ram so that his head struck each seat as they took him to the back of the bus,” said Rebecca Heinegg, an attorney for Guest. “They were clearly aware that this was happening.”

Guest and eight other protesters, none of whom was charged with a crime, are suing Bovell, several of his colleagues, the NYPD and city authorities for allegedly violating their constitutional rights by arresting them. They are seeking unspecified compensation, damages and legal fees.

In a response filed before Bovell was named as one of the officers involved, lawyers for the city denied all the protesters’ allegations. They also requested on various legal grounds that the lawsuit be dismissed in its entirety.

“At all times relevant to the acts alleged in the complaint, defendant City, its agents and officials, acted reasonably, properly, lawfully and in good faith in the exercise of their discretion,” the response said. A spokeswoman for the city’s law department declined on Thursday to comment on the record about the update naming Bovell.

McMillan’s attorney, Martin Stolar, said he intended during her trial to question Bovell about his alleged injury of Guest.

“This suggests a police officer who is not afraid of using force when it is not required,” Stolar told the Guardian. “It certainly adds to Cecily’s case.”

Stolar last month had a motion requesting access to Bovell’s NYPD personnel file rejected by Judge Ronald A Zweibel, who said the attorney had “failed to even establish that ‘prior misconduct’ of any sort has been found, or documented, by the NYPD against Officer Bovell”.

The response filed by the NYPD to Stolar’s motion did, however, confirm that Bovell had been subject to at least two inquiries by the force’s internal affairs bureau. It said that he received a “command discipline” for failing to radio that he and his partner were pursuing a 17-year-old boy who was riding a dirt bike in the Bronx in March 2010.

The boy, Reginald Wakefield, later sued Bovell and several colleagues, claiming he was intentionally run down and sent flying head-first into a street lamp. He said he was left with broken teeth and a wound requiring stitches in his head. The NYPD said Reginald “refused to stop and ended up hitting a parked department vehicle”. The lawsuit was dismissed last year.

Stolar also alleged in his motion that Bovell had been filmed on video surveillance kicking a man on the floor while arresting him in a Bronx bodega in 2009. The NYPD said in its response that officers had struggled with a suspect who had a knife, and that an inquiry by internal affairs concluded that an allegation that Bovell injured him in custody was “unsubstantiated”.

McMillan’s attorney also said that he had seen documents showing Bovell was involved in the 2011 Bronx ticketing scandal, in which officers were charged with covering up hundreds of traffic offences as favours for relatives and friends.

The NYPD said in its response that “an allegation of ticket fixing is immaterial as to either Officer Bovell’s alleged propensity to physically abuse or sexually assault a prisoner held in police department custody”.