Speaking on ITV’s After the News, the Manchester Central MP said: “One of the key questions you are asked when you become a candidate for the Labour Party - and you have to sign a contract to say this - is there anything in your past that would bring the Party into disrepute? And I don’t understand in all honesty Jared could have signed that paper."
“That’s why I think he should be suspended while that investigation is taking place,” she added.
Labour launched a probe into O'Mara’s alleged remarks a day after he on the Commons Women and Equalities Select Committee after it was revealed he joked about having an orgy with members of the pop group Girls Aloud in 2004.
The MP "categorically denies" claims made by his Sheffield Hallam constituent Sophie Evans about an incident in March this year.
As well as comments about Girls Aloud, O'Mara had claimed Michelle McManus only won Pop Idol "because she was fat" and suggested it would be funny if jazz star Jamie Cullum was "sodomised with his own piano".
The MP apologised for the offensive comments, which were first revealed by the Guido Fawkes website.
O'Mara ousted former deputy prime minister Nick Clegg in the June election to become MP for Sheffield Hallam.