Conservative councillor Daniel Cook told Channel 4 News that Mr Pincher groped him in 2005 and 2006. Mr Pincher has been suspended by the Tory party.
Mr Cook, the deputy mayor of Tamworth in Staffordshire, where Mr Pincher is an MP, said he had filed a complaint with the Conservative Party.
According to Channel 4, Mr Pincher denies the latest allegations.
The BBC has contacted him for a response.
Mr Cook, a former council leader who waived his anonymity for the interview, expressed his outrage at what had occurred and demanded that Mr Pincher be expelled from the Tory party.
Mr Pincher was suspended after allegations surfaced last week that he groped two men in a private members’ club.
Prime Minister Boris Johnson was then grilled by members of his own party about what he knew and how he handled the allegations.
On Tuesday, he apologised for appointing Mr Pincher to the government position, admitting he had been informed about a complaint in 2019 and admitting he had made a “bad mistake.”
Minutes after the prime minister’s statement, a slew of government resignations followed, including former health secretary Sajid Javid and chancellor Rishi Sunak.
Boris Johnson has stepped down as Conservative Party leader.
Mr Pincher is facing a slew of allegations of inappropriate behaviour dating back several years, all of which he denies.
Two police forces investigated two allegations of sexual assault by a man identified as Mr Pincher, one in London between 2010 and 2012 and another in Staffordshire in May 2019.
Both investigations yielded no results, and Mr Pincher denies the allegations.
Mr Cook said he met Mr Pincher when he was about 28 years old and running for council in Tamworth in the 2004 elections.
He campaigned alongside Mr Pincher and others, and Mr Cook claimed the parliamentary candidate took him under his wing.
According to the councillor, Mr Pincher was drunk on both occasions when he was assaulted.
Mr Cook claimed that in 2005, while his wife was at work, Mr Pincher and a council colleague came to his house and “cupped his hand around my genitals” before asking if he had any “good porn.”
He claimed that a year later, Mr Pincher had returned to his house “stinking drunk,” cupped him again, and grabbed him from behind.
Mr Pincher referred to his Conservative colleague as a “rising star” in Tamworth politics, according to the councillor.
Mr Cook stated that the first time he reacted by laughing it off and pushing him away, but the second time he threw him against a fridge and physically threw him out of his house, watching him stagger down his driveway.
He stated that he was angry about what had occurred and that he had come forward after other allegations had been made.
Mr Cook added that if he had spoken up at the time, the situation could have been resolved sooner.
“Mr Pincher’s membership in the Conservative Party has been suspended pending investigation,” a Conservative Party spokesperson said.