Actress Gillian Anderson, 38, who recently welcomed son Oscar with partner Mark Griffiths, is rumored to be facing a paternity test. Anderson's estranged husband Julian Ozanne is suspicious as to whether the baby's biological father is himself or Griffiths.

An allegedly close source said: "The split has been very hard for them both, but Julian has not ruled out the possibility he might be the father. Gillian and Julian split in April and she announced her pregnancy when she was three months gone, so the timing is pretty close. Julian wants to be sure. He has spoken to several people about this and they have all told him to get a paternity test carried out - which he is seriously thinking about." Gillian and Julian were married for 16 months before the separation.