A used-car salesman who murdered his estranged wife, their son and his father-in-law by setting fire to their home following the collapse of their marriage has been jailed for life.

A judge told Iraqi-born triple killer Danai Muhammadi, 24, that he will spend at least 38 years behind bars before being eligible for parole.

Fuelled by anger, spite and resentment, he killed Melissa Crook, 20, and their 15-month-old son Noah by torching the house in Chatham Hill, Chatham, Kent.

Mrs Crook's father Mark Crook, 49, was left critically ill with severe burns in hospital following the fire just before 2.30am on September 10 last year. He died six days later.

Sentencing at Maidstone Crown Court, Judge Mr Justice Sweeney said: "It can truly be described as pure, selfish wickedness."

Muhammadi and his friend, nightclub bouncer Farhad Mahmud, 35, squirted petrol through the letterbox using a garden sprayer before igniting it, leading to fire breaking out at the base of the stairs.

Flames cut off any escape route for the family who were asleep upstairs at the time as fire and dense smoke filled the three-bedroom property.

Last month, Muhammadi and Mahmud were each found guilty of three counts of murder and two counts of attempted murder in relation to Mrs Crook's mother Amanda, 50, and brother Bohdan, 22, who survived.

Muhammadi's girlfriend, Emma Smith, 22, was convicted of three counts of manslaughter but cleared of murder and attempted murder following a six-week trial. Prosecutors said unemployed Smith "encouraged and goaded" Muhammadi and exchanged hate-filled texts and online messages with Mrs Crook before her death.

Mahmud was sentenced to life with a minimum term of 34 years prison before being eligible for parole.