A BRITISH man has appealed against his convicted for shooting dead his American wife and nine-month-old daughter.

Neil Entwistle, who who met his wife Rachel at York University, says he should get a new trial because police searched his home without a warrant when they came to check on the well-being of his family.

Entwistle was convicted in 2008 of the murder of his wife and baby daughter, Lillian Rose, in Massachusetts.

Prosecutors say Entwistle had become despondent after accumulating tens of thousands of dollars of debt and had complained about his sex life with his wife.

Entwistle's lawyer is arguing that evidence taken from the home was seized illegally.

Prosecutors have said police were justified in entering the home because they were responding to the pleas of concerned relatives and friends.