The man who admits starting a fire that killed a mother and her two children threatened to “destroy” the youngsters’ father only weeks before the fatal blaze, a jury heard.

In a series of text messages, Asjid Mahmood suggested ways of getting back at Zaheer Shah “to see him suffer”.

Mr Shah’s daughter, Alina, ten, and son, Aman, eight, died in a fierce fire that engulfed their home in Hendford Drive, Pollard Park, Bradford, on July 6 last year. Their mother, Iram Shah, Mr Shah’s former wife, died six days later after leaping from the blazing building with her clothing in flames.

Asjid Mahmood, 22, and his brother, Arshed, 18, both of Pollard Lane, Undercliffe, Bradford, deny murdering Mrs Shah and the two children. Asjid Mahmood admits starting the fire but says he did not intend to cause death or serious injury.

One of Mr Shah’s former partners, Serra Gibbons told Bradford Crown Court yesterday she began a relationship with him in 2008 and they have a son together.

In May and June last year, Asjid Mahmood, known as Ash, began sending her up to five text messages a day.

Miss Gibbons told the jury Ash was quiet and timid and Mr Shah treated him “like a dog”. Ash drove him around and ran errands for him.

Ash told Miss Gibbons that Mr Shah had ruined his life and was going to suffer, the court was told.

In the text messages, Ash says: “we will get him back and play him how he’s played us” and “I am so angry, I want to destroy him. I can’t destroy him physically but I am going to ruin him in every other way”.

The trial has heard that Mr Shah immediately blamed Asjid Mahmood when he learned of the fatal fire, telling him: “I know you’ve done this.”

Asjid Mahmood accused Mr Shah of ripping him off over loan payments for a new Seat Leon FR car they bought between them to rent out.

He branded his former friend “heartless, greedy and selfish” and accused him of cheating his brother, Arshed, out of £500.

The defence case in the trial was due to start today.