A man accused of murdering his ex-girlfriend’s brother searched “spear gun death accident”, “murder by mental illness” and “sentencing for murder in the UK” on the internet in the days leading up to the alleged murder.

Financial expert, Andrew Morris, 30, of Lavender Sweep, Battersea, was found with a harpoon stuck in his head after he allegedly killed his housemate Henry Stangroom, 21, by stabbing him in the heart, lungs and head in revenge for his sister Michelle Stangroom, 28, breaking up with him.

The former Cambridge mathematics student has been giving evidence for two days at the Old Bailey, over Monday and Tuesday, describing the events that led to the day Mr Stangroom died, October 17, last year.

Days before the incident, while Mr Morris was off work the jury were told he searched online for how long it takes for someone to bleed to death, spear gun death accident, and harpoon shot through the mouth.

Mr Morris said the searches were related to what he had been watching on the television.

When Mr Morris was arrested for murder he told the police the last thing he could remember was hugging former girlfriend Miss Stangroom on the doorstep a few days previously.

However, at close of play on Tuesday the jury were told Mr Morris’ memory of the incident had returned.

He said: “My memory of that evening and that morning is probably not as clear as my memory of maybe other days around it, but I have certainly recovered a significant amount of memories around the events of that day.”

Earlier Roderick Johnson QC opened the defence case on Monday morning and questioned Mr Morris about his childhood and relationship with his father.

The jury heard the discovery of brutally explicit sexual images drawn by his father led to a family breakdown when Mr Morris was 21, and only in December when his father visited him in prison, did he hear these were inspired by sexual abuse his father had witnessed as a child.

The court also heard Mr Morris has had a chequered romantic past.

He fathered a child with girlfriend Laura Teague, but while she was pregnant began a relationship with Miss Stangroom, who he worked with.

He said Miss Teague had stopped him seeing his son after they split and her father was demanding money, inducing his anxiety and depression.

Work stresses were also heard, and the jury was told Morris, a regular cocaine user began self harming and took a paracetamol overdose.

Previously the court had been told Miss Stangroom was physically attacked during an argument before she moved out of the flat shared between the three on August 29.

Mr Morris claims he was trying to restrain her.

The trial continues.