A murder suspect said it was "destiny" his wife and toddler son died in a fire and laid into British police, saying: "When a child dies the police go and arrest the parents."

Danai Muhammadi made angry speeches on a dramatic fifth day in the witness box at the Chatham Hill murder trial.

Crying, shouting and smiling in disbelief, he denied killing his wife Melissa Crook, 20, their son Noah, 15 months, and her father Mark, 49, by starting a fire which ripped through their Chatham Hill home on September 10.

Muhammadi said: "It seems a custom in this country that when a child dies the police go and arrest the parents of that child. There's no morals, no humanity in them."

The court was packed on Wednesday for fierce cross-examination by chief prosecutor Mark Dennis QC, who claimed Muhammadi was filled with "spite, anger and resentment" after Melissa left him.

Mr Dennis told the murder accused: "You were by that house around 2.30am on that morning [having borrowed] a spray container which you filled with three litres of petrol.

"Do you have the courage today to own up to that dreadful act?"

"No, I haven’t done it," the car salesman replied.

Mr Dennis said: "Do you think people normally walk through the streets at 2.30am with a spray canister filled with petrol just in case they have the urge to set fire to something?"

Mark Crook (left), his daughter Melissa and her toddler son Noah were killed in a house fire

Thumping the witness box with his hand, the 24-year-old said: "Have you seen it by your own eyes? Do you have evidence beyond doubt, 100%?"

Pointing at himself, he added: "Did anyone see this person there, that he was carrying a can? You are following the words of some stupid animals. You have no proof."

Mr Dennis said: "I have, we're sad to say, three people who have been put to a grave.

"That is a fact, Mr Muhammadi, and petrol doesn't suddenly appear."

The car salesman told the court he was blackmailed by two men who threatened to burn the house if he didn't pay £5,000.

He drove from his Coventry home to Gillingham to meet them, he said, but did not hand over the cash.

But Mr Dennis told jurors Muhammadi revealed the story just two weeks before the trial.

He demanded: "Were you waiting to the last moment to fit a defence into all the evidence?"

Police at the scene of the house fire in Chatham Hill

Mr Dennis said Muhammadi would "anticipate" murder if he started a fire.

"No I don't know that, okay," Muhammadi replied. "Whoever has done it must have not meant to kill, because the money they asked for it wasn’t worth killing for.

"The person who commits such a thing is not a human, it must be a person with no heart, no feelings, because a child is involved."

He added: "What do you mean, 'anticipate'? If God and destiny don't want someone to die, nothing happens to them."

Mr Dennis replied: "You believe we have all got a destiny and that death may come tomorrow?"

"Yes," Muhammadi said.

Muhammadi, of Britannia Street, Coventry, denies three murders and the attempted murders of Melissa's mother Amanda and brother Bohdan.

His new girlfriend Emma Smith, 21, of Barley Lea, Coventry, and bouncer Farhad Mahmud, 35, of Fernhill Road, Maidstone, deny the same charges.

The trial continues.