The woman, who refused to be identified and was only known as Anna, said she believes she was taken onto a spacecraft where the bizarre operation took place.
Anna is one of thousands of people, including doctors, lawyers, and pilots, who claim to have been taken by aliens.
She said: “They wanted some help with their hybrid project, so they chose me.
“I discern who I tell and who I don’t because I can tell who’s ready for that information and who’s not.
“I don’t want to freak people out.”
The woman spoke out at the world’s first conference which intended to convince the globe that alleged alien abductions are a positive thing.
The Close Encounters Conference in Byron Bay, New South Wales, Australia, saw believers turn up to share stories.
The results of a survey of nearly 3,000 people who claim to have been abducted were also reported at the conference which ended yesterday.
The survey was conducted by the Edgar Mitchell Foundation for Research into Extraterrestrial Encounters (FREE), set up by the late astronaut who walked on the Moon.
FREE board member and researcher Mary Rodwell presented the survey’s initial findings at the conference.
She said: “They’ve talked about seeing strange craft in the sky, being taken to a spacecraft, procedures being done to them, being educated on the craft.
“And what we’re finding is that 85 per cent of people change their lifestyle after these experiences.
“What we’re finding is that people are speaking about their experiences in an overwhelmingly positive way.
“Their attitude to the materialistic world changes, they become more ecologically minded, they feel more empathy for the planet and themselves, and they are being changed in ways that many people can’t understand.
“When you hear doctors, nurses, social workers, pilots, celebrities, lawyers, farmers, children, talking about this experience … when they’re all talking about similar things and similar patterns and you hear the emotion and the feeling, all of that is an authenticity you cannot dismiss.”
Kathryn Hand organised the conference and said people had previously feared speaking out for fear of being called insane.
She said: “We found that by organising this, people have started to feel more comfortable talking about it. We’re giving them a platform to talk about it.
“People are scared that if they start talking about it too openly other people might think they’re crazy.
“We’re bringing people together who have had encounters, and trying to make it something that can be discussed in an environment where they won’t be ridiculed and where they can discover they’re not alone.”