Seema Malhotra formally complained to Commons Speaker John Bercow, saying the "privacy, security and confidentiality" of her MP's office had been violated.
She also said her staff had felt "harassed, intimidated and insecure".
A spokesman for Mr Corbyn said an aide had been checking when the office would be vacated, and denied intimidation.
Ms Malhotra resigned as shadow chief secretary to the Treasury last month in protest at Mr Corbyn's leadership and is now backing leadership challenger Owen Smith.
In a statement, Ms Malhotra said staff working for Mr Corbyn and shadow chancellor John McDonnell had gained "unauthorised entry into my office in parliament".
The MP for Feltham and Heston described several incidents when people from the leader's office used digital keys to open the office door.
"The implications of this are extremely serious," she said.
"This is a breach of parliamentary privilege and is a violation of the privacy, security and confidentiality of a member of parliament's office.
"Furthermore, my staff, including an intern, who have always been courteous and open, have felt harassed, intimidated and insecure and decided themselves it would be best to not leave anyone alone in the office."
She has complained to Mr Bercow and to Mr Corbyn and called for a formal investigation.
A spokesman for Mr Corbyn said accusations Karie Murphy - the Labour leader's office manager - had intimidated anyone were "untrue".
He said Ms Murphy had been checking to see if the office had been vacated by Ms Malhotra following her resignation.
"As an office manager on the leader of the opposition's floor, Karie has a key to open all offices. She accessed the office in question to confirm when it would be vacated.
"It is a month since Seema Malhotra resigned as shadow chief secretary to the Treasury, and the office is intended for the person holding that position."
BBC political correspondent Carol Walker said the incident was "another extraordinary twist in Labour's increasingly bitter internal battle".
The complaint comes after more than 40 female Labour MPs wrote to Mr Corbyn saying he had failed to do enough to prevent "disgusting" threats against members.
The group of female MPs - including former shadow ministers Heidi Alexander, Paula Sherriff and Kerry McCarthy - say intimidation has been carried out in Mr Corbyn's name.
Speaking on Saturday, Mr Corbyn condemned abuse among members, saying "it has no place in our party".
He said: "I don't do personal abuse, I don't respond to personal abuse, I condemn any abuse from others."
Meanwhile, leadership rival Mr Smith said his wife, Liz, had been a victim of online abuse and claimed there was now a level of abuse, anti-Semitism and misogyny in Labour that was not there before Mr Corbyn became leader.
"My wife stood recently for a community councillor position in the village where we live in South Wales and was subject to a torrent of online abuse. It's a community council position."
He added: "I think it's just absolutely unacceptable."
Mr Corbyn is facing a challenge from the former shadow work and pensions secretary, after Labour MPs overwhelmingly backed a motion of no-confidence in their leader.
The winner of the leadership contest will be announced on 24 September.
A former Labour shadow cabinet minister has accused an aide to leader Jeremy Corbyn of entering her parliamentary office without permission.