Cornell, who is currently writing Action Comics for DC, previously penned 'Father's Day' for the programme's first series in 2005 and later returned to write the two-part 'Human Nature/The Family of Blood'.
According to his agent's website at The Agency, Cornell has been comissioned to write a new episode for the next series.
Tom MacRae - who previously wrote 'Rise of the Cybermen' and 'The Age of Steel' for the second series of the programme - is also listed as having a script in development.
However, Cornell dismissed the news as "rubbish" on his Twitter feed.
Doctor Who will return to BBC One for a one-off special this Christmas, with the sixth series expected to follow in 2011.