A man accused of murdering his pregnant ex-wife with a crossbow has claimed he only intended to get her attention when he fired the bolt.

Ramanodge Unmathallegadoo is accused of murdering Devi Unmathallegadoo, 35, after their marriage broke down and she left him for another man.

The 51-year-old armed himself with two crossbows and hid in a shed at the home Ms Unmathallegadoo shared with her new partner Imtiaz Muhammad on the morning of November 12 last year.

Unmathallegadoo claimed he only had the loaded weapons to prevent himself being intimidated by Mr Muhammad when he came to confront them.

But the jury were told on Friday that Unmathallegadoo had been stockpiling weapons and equipment for more than a year before the killing.

He had acquired two crossbows and numerous arrows or bolts with which to carry out the attack, jurors were told.

The Old Bailey heard Unmathallegadoo had lived at the address on Applegarth Road in Ilford, east London, for five months before he split from his wife and knew the layout well.

In his evidence, the defendant described spotting Mr Muhammad in the garden from the shed and chasing him through the house towards the stairs.

When asked why he had the crossbow, Unmathallegadoo said: “It was there only as a deterrent because I didn’t want to be intimidated physically by Imtiaz.”

He said he had dropped one of the crossbows in the kitchen because he could only aim one at a time.

“Devi and Imtiaz were on the stairs. I just wanted them to stop (running) – I thought if I hit the banister they would hear the noise and stop,” he said.

“I moved the crossbow to check if the safety catch was on or off – I was just checking and it went off.”

He added: “While I was checking the safety catch, the next thing I know there was a bang.”

Unmathallegadoo said his finger had been on the crossbow while he checked the catch.

When asked what he had been intending to do, he said: “I would have checked the safety catch and then aimed at the banister.”

Unmathallegadoo admitted he had not simply said the word “stop”.

He also said his first reaction was to go and fetch the second crossbow, adding: “When the crossbow had been discharged, I felt defenceless so the next thing I did was go back to the kitchen and get the other one.”

The defendant said he had not seen that Mrs Unmathallegadoo had been hit.

The crossbow bolt penetrated her body, causing “catastrophic” internal injuries, including piercing her heart, jurors heard.

Medics were unable to save her, but her baby was delivered by emergency Caesarean and survived.

Prosecutor Richard Horwell QC told jurors: “This was a deliberate and quite calculated act of revenge on his part, intended to cause at the very least the death of Devi.

“On the evidence you hear, however, you may well conclude that his plans encompassed more than that and that, although Devi was undoubtedly his principal target, he also intended to kill her partner, Imtiaz Muhammad.”

The defendant also allegedly carried out surveillance on the family home.

Unmathallegadoo denies murder and the trial continues.

Additional reporting by Press Association.