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The former frontbencher, who represents Luton North, has had the whip withdrawn while an investigation into the claims is carried out.
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.”
Labour MP suspended from party following “allegations”