He became a well-known character during the protests, regularly speaking to the media.
The second rape is alleged to have taken place on January 21.
The woman also claims she was raped a third time, when she was bound with cable ties – but Blackman has not been charged with this offence.
The alleged victim, who cannot be named, lived at home in south London during the week, and slept in the Occupy tent at weekends.
The woman admitted she was expelled from the Anonymous Facebook group by Blackman, along with others, after angry exchanges about the group. She also admitted confronting him over a relationship he had started with another woman.
