Catherine Tate is being tormented by a poison pen fiend falsely accusing her of cheating on her husband, according to The Sun.

A series of sinister letters have been sent to the star’s home this month.

Police are investigating after being contacted by a man – thought to be Catherine’s husband Twig Clark, 36.

The level of abuse aimed at 41-year-old Catherine has left her very concerned.

A source said yesterday: “The letters were nasty and caused great alarm. They contain completely false allegations. Catherine is understandably incredibly upset. It’s very sinister.”

The notes were sent over several days to Catherine’s home in Richmond-upon-Thames, South West London.

A Met Police spokesman said: “Police received a complaint from a man on Sunday regarding malicious communications. Detectives are investigating.”

A family friend yesterday added: “Catherine and Twig are wondering what type of crank would send letters like these.

“They’ve been through a difficult patch recently and this is the last thing Catherine needs.”

Her agent refused to comment last night, saying: “We don’t talk about clients’ private lives.”