Bloom, who has starred with and romanced some of Hollywood's greatest actors in a 60-year career, will appear next year alongside David Tennant, in his final outing as the Doctor.
"It is happening. They are filming at the moment.
I have been organising her schedule," her manager in America, Marion Rosenberg, is reported to have told the Daily Mail.
Bloom, 78, who lives alone in Fulham, north London, rose to prominence after being chosen by Charlie Chaplin to appear in his film Limelight in 1952. She is said to be excited by her new role.
A friend of the actress told the newspaper: "The script is a very closely guarded secret, as the producers are desperate for Claire's appearance to be a surprise."
Bloom is well known for playing Blanche DuBois in A Streetcar Named Desire in both London and New York. She desribed the role as her favourite.
She had a relationship with Richard Burton after they appeared together in Hamlet, Look Back In Anger and in the film The Spy Who Came In From The Cold.
She was married three times, first to the actor Rod Steiger, next to the producer Hillard Elkins and finally to the novelist Philip Roth.
A BBC spokesman declined to comment.
The Telegraph and Mail are claiming 78 year old Claire Bloom, a Hollywood actress, is to appear in Doctor Who, playing the Doctors Mother!
A BBC spokesman declined to comment, but Claires manager in America, Marion Rosenberg says It is happening.
They are filming at the moment.
I have been organising her schedule.