Labour MP Kelvin Hopkins has been suspended from the party “on the basis of allegations received”, a spokesman said.
The former frontbencher, who represents Luton North, has had the whip withdrawn while an investigation into the claims is carried out.
Mr Hopkins, a former shadow culture secretary under Jeremy Corbyn, faces claims he sent suggestive texts and behaved inappropriately.
Ava Etemadzadeh, 27, told the Telegraph she had invited the MP to speak at an event at Essex University in 2014 in her role as chairwoman of its Labour society.
Ms Etemadzadeh informed the whips office at the time of the incident and said a local party member contacted the Leader’s office last year to raise concerns about the allegations.
It is understood that she made fresh allegations when she contacted the party today.
Labour said it takes complaints “extremely seriously” and has “robust” systems in place to deal with them.
A spokesman said: “On the basis of allegations received by the Labour Party today, Kelvin Hopkins has been suspended from party membership, and therefore the Labour whip, while an investigation takes place.
“The Labour Party takes all such complaints extremely seriously and has robust procedures in place to deal with them.”
Mr Hopkins employs his wife Patricia as a part-time constituency secretary.
A woman at his home who said she was his wife said the MP was at a meeting in Luton this evening.
Asked about the suspension, she said: “I don’t know anything about it.”
Mr Hopkins, 76, has been an MP for 20 years and has remained on the backbenches except for a four month stint as culture spokesman last year.
On the left of the party, he has a long history of involvement in the trade union movement and was one of the 36 MPs to nominate Mr Corbyn when he stood for the Labour leadership in 2015.