Police are investigating the death of an 11 week old baby, who passed away in hospital overnight.

A 36 year old Launceston man was charged on Tuesday with assaulting his 11 week old daughter.

The man, who cannot be identified for legal reasons, was charged with three counts of Criminal Code assault on his daughter.

The man was also charged with common assault on his 36 year old wife.

The man appeared in the Hobart Magistrates Court on Tuesday and has been remanded in custody until 9 March.

Investigations are continuing and further charges may be laid in relation to this matter.

The matter has been referred to the Coroner and a coronial case has been opened.