A DAD who killed his wife and two children may have been using prescribed anti-smoking medicine with possible side effects of "anger" and "depression", an inquest heard.

Andrew Case had been trying to quit smoking for some time before he stabbed wife Victoria and killed his two children before hanging himself, a coroner was told.

Two empty packs of the prescribed drug Champix were found in the kitchen of the home when police were examining the gruesome scene.

But Southampton Coroner's Court heard how there was no trace of the medicine in the 33-year-old's body when it was later examined by a pathologist.

The court was told how Victoria's mother Linda Haskell, 56, walked in to the house to be confronted by the scene of horror.

She found Victoria lying dead in the living room with her two children Nereya, 18 months and Phoebe, 2, by her side.

Pathologist Basil Purdue suggested Victoria, 31, may have been killed in her sleep. She had received a 7cm knife wound to the base of the neck.

Phoebe had been smothered to death. Nereya's cause of death was unclear, though smothering has not been ruled out.

Andrew Case, the court heard, may have been alive for up to a day after killing his family.

He then used a washing line to hang himself from the banisters of the stairs in the home.

Alcohol measured in his blood was more than twice the drink drive limit.

The family had only recently returned home from a holiday in Weymouth and everything appeared to be 'normal' in the run up to the tragedy, on July 26 last year.

And on the evening of July 24, Mr Case was seen at a local pub asking for cigarettes.

Det Chief Insp Chris Fitchet said the family had been suffering from financial problems.

But coroner Keith Wiseman said there was 'an absence of real explanation' as to what had happened.

He added that the anti-smoking medicine may not have been used by Mr Case for 'several days' prior to the deaths based on how levels of the drug in someone's system reduces by 50 per cent per day if it is not taken.

He ruled that Victoria, Phoebe and Nereya had been unlawfully killed and that Mr Case took his own life.