A “manipulative” allotment owner with a “volatile” temper has been found guilty of beating and then strangling to death an elderly widow to avoid being thrown off his north London plot. 

Rahim Mohammadi killed 80-year-old Lea Adri-Soejoko using lawnmower flex and hid her body in a shed at Colindale allotments in February last year.

The defendant made no reaction as the jury delivered its guilty verdict on Thursday, watched in silence by his victim’s family who held hands in court.

But as he was led from the dock, Mohammadi turned to the jury and said: “You will have that on your conscience sending an innocent man to prison.” 

Adri-Soejoko, the allotment secretary, was found after her family raised concerns that she had failed to turn up at a meeting.

She had clashed previously with Mohammadi at an allotment association meeting. During a heated discussion over evictions, she had told him to “shut up”. He called her a “bloody old witch”, in reply, the court heard.

Prosecutor John Price QC had told jurors the Iranian had a reputation for having a “volatile” temper and his ambitions to take over running the allotment made Adri-Soejoko wary of him.

The row culminated in Mohammadi beating up Adri-Soejoko on the allotment, causing bruises and fractures to her ribs.

The prosecution alleged he then throttled her with the mower flex to stop her from reporting the attack, which would have led to his eviction.

Price said: “Adri-Soejoko was beaten up. That in turn does point to a motive for her murder – to avoid detection for a shocking and very serious assault on a vulnerable old lady.”

The victim’s body was locked up in the mower shed, which only four key-holders had access to, including Mohammadi and Adri-Soejoko, whose set were in her pocket.

The prosecution said Mohammadi had planned to move her to avoid suspicion being cast at him, but police following the sound of her ringing phone found the body before he could act.

His DNA was found on the cord used to strangle her and he was caught on CCTV coming and going from the allotment, jurors were told.

He had been involved with the allotment since 2008 through Freedom from Torture, an organisation helping torture victims suffering from post-traumatic stress disorder.

The court heard Mohammadi sought political asylum in Britain in 2005 and was given indefinite leave to remain in 2010.

Giving evidence, he said he had gone to the allotments to buy opium for his bad back on the day of the killing.

He claimed he heard shouting but dismissed it as a drunken fight.

Adri-Soejoko’s children and grandchildren attended court throughout the trial.

In police interviews, Mohammadi gave different and inconsistent accounts of his movements.

DNA belonging to a second suspect was retrieved from the victim’s right hand, but extensive inquiries found he had been nowhere near Colindale.

Speaking after the verdict, Detective Chief Inspector Noel McHugh, from Scotland Yard, said: “Although I never had the privilege of meeting Lea, we have learnt what a lovely, caring lady she was, like everyone’s mum or gran.

“She was a real pillar of the community, a sprightly 80-year-old grandmother who was very active in her local neighbourhood and secretary of Colindale Allotment Association.

“We don’t know exactly what happened on the day Lea was killed, but we know there must have been some kind of argument which led to Mohammadi brutally attacking her. Knowing he would be in very serious trouble for what he had done, he went a step further and murdered her in the hope he would never be found out.”

Judge Richard Marks QC adjourned sentencing until Friday.