Detectives are offering a £20,000 reward as they hunt for a suspect with at least four aliases over the murder of an grandmother who was found strangled at her allotment.

Belgium-born mother-of-three Lea Adri-Soejoko, 80, was found dead in a lock-up store at the allotment in Colindale, north-west London, on February 28.

A post-mortem examination found she had been strangled with the cord of her own anorak and the cable of the lawnmower, which was stored in the shed.

Police are offering a £20,000 reward as they hunt for Mubarick Duat (left) over the murder of grandmother Lea Adri-Soejoko (right) who was found strangled at her allotment

Rahim Mohammadi, 40, who moved to Britain from Iran 10 years ago and also had a plot at the allotment, was charged with the murder of Ms Adri-Soejoko on March 5.

Now the Metropolitan Police are seeking Mubarick Duat in connection with her death.

He is also known as Mubarick Duah, Kwaka Duah and Mubarice Duah along with numerous other aliases.

As they launched the appeal, Scotland Yard warned the public not to approach the 37-year-old.

The allotment owner (pictured) was strangled with the cord of her own anorak and the cable of the lawnmower stored in the shed

He is is described as black, slim and 5ft 8ins and 'can be violent', the force said.

Detective Chief Inspector Noel McHugh, who is leading the investigation said: 'We urgently need to trace Duat in connection with this murder.

'There is a substantial reward on offer and I hope it encourages someone to come forward with information that leads to Duat's arrest and prosecution.'

He added that is was 'crucial' he is detained 'as soon as possible'.

The man being sought is known to have previously frequented the areas of Hackney, Dalston, Malden, Colindale, Thornton Heath, Wimbledon, Hammersmith and Fulham, the Met said.

When the investigation was launched, officers said they were tracing rough sleepers in the area.

The doors of the shed where Ms Adri-Soejoko was found - which allotment members used as an office to store their garden tools - appeared to be damaged around the lock, indicating a break-in may have taken place.

Gardeners that used the 95-plot allotment added that money was kept in the shed and that two gaping holes had been made in the surrounding 6ft tall wire fence.

Ms Adri-Soejoko, described as a 'pillar of the community', was found in the shed after her family raised concern when she did not attend an allotment meeting of the Colindale Allotment Garden Association.

The shed where she was found, which had a torn Portuguese flag flying from its roof (pictured), backs onto a row of semi-detached houses

Ms Adri-Soejoko, described as a pillar of the community, was the secretary of the local allotment society (pictured)

She was found 25 minutes after she was reported missing. She is also known by her maiden name of Lea Hulselmans.

Ms Adri-Soejoko's family said: 'What is keeping us going is the hope that we will find out the truth about the callous death of our kind and loving mum.

'We need your help, the public, to support us now by assisting the investigation and helping to shed light on Mum's final hours and by finding Mubarick Duat.'

Anyone who sees Duat should not approach him but call 999 immediately.

Anyone with information should contact the incident room on 020 8785 8099, police via 101, or Crimestoppers anonymously on 0800 555 111.