The English actor Dean Gaffney recently made a comment on his Twitter account about appearing in Doctor Who. The actor, who is most famous for playing Robbie Jackson in Eastenders from 1993 to 2003, said that he is busy filming for Doctor Who, but it is currently unknown what episode he will be in, although it is rumoured to be the the episode after Planet of the Dead, which is currently filming. It is believed that this news will officially be confirmed in the next issue of Doctor Who Magazine which is out next Thursday.
Update: It seems that Dean Gaffney's Twitter account is fake, sorry for an inconvenience caused.