Steven Moffatt didn't like her character Rose
Her character Rose Tyler left with a clone of the Time Lord, played by David Tennant, 37, in the fourth series finale.
And Steven, 47, who has taken over from Russell T Davies, 45, reckons it was a smart way to ditch the Doctor’s sidekick.
‘You have to hand it to the Doctor for dumping a slightly needy girlfriend by palming her off on a copy of himself,’ he told fans at a sci-fi convention.
‘He tried leaving her in a parallel universe and that didn’t work!’
Billie, 25, who is expecting her first child with husband Laurence Fox, 29, played the Doctor’s assistant in the first 2 series.