Ms Bailey, who was 19 at the time of the Labour Party gathering, told BBC Radio Four's PM programme she did not get the support she needed when reporting the incident to a senior official two years later.
Labor Party supporter Bex Bailey said she was raped at a party event in 2011 by a senior party member but was told not to report it because the incident could "damage" her.
It has been another profoundly upsetting day in the unfolding scandal of sexual harassment and abuse in parliament and political parties.
A Westminister staff member alleged that an unnamed MP sexually assaulted her during a parliamentary trip in 2016.
"Some of the people who knew what happened to me are now being tasked with fixing this broken system and those are the very people who in my opinion at best turned a blind eye and at worst actively covered it up", she said. She is showing great bravery and courage in speaking out.
Meanwhile, The Scotsman says that First Minister Nicola Sturgeon has warned about a cultural problem with "the behaviour of men" as she ordered a review of the way the Scottish government deals with complaints of sexual harassment.
"It was quite a frightful experience and this is why I've been fighting so hard for changes to the way that we do this".
Describing Ms Bailey as "a strong and incredible young lady" she said: "The Labour Party is extremely serious about tackling any form of abuse and making sure we have a transparent structure in place", she said. She said: "he is deeply disappointed and distrustful, and she tells me that distrust is endemic".
Bailey says she was not "signposted" to anyone who could provide advice.
Labour's process relies on people reporting an attack to someone within the party - who is "inclined to be loyal to the Labour Party", she said.
She said that since joining the NEC she has tried to make changes, but it has proved "frustrating".
"I have asked Labour's general secretary, Iain McNicol, to launch an independent investigation into the allegations that she wasn't given the support from the party she should have received and had the right to expect", said Corbyn. It takes great courage for victims of rape to come forward - and all support must and will be made available to them.
Mr Corbyn added: "There will be no tolerance in the Labour Party for sexism, harassment or abuse.
Where an allegation concerns a matter which might amount to a criminal offence, such as a sexual assault, we would advise the individual to consider contacting the police in the first instance".
A Labour Party spokeswoman said: 'The Labour Party takes these allegations extremely seriously.
BBC political editor Laura Kuenssberg described the list as "both a mixture of unsavoury allegations, reports of well-known relationships, and some claims that are furiously denied".