The alleged mastermind behind the daylight execution of a criminal lawyer at a busy shopping centre in western Sydney is the third person to be charged with his murder.

Key points: Ho Ledinh was a prominent lawyer whose 2018 death shocked Sydney's Vietnamese community

Ho Ledinh was a prominent lawyer whose 2018 death shocked Sydney's Vietnamese community Police allege the murder was prompted by a dispute over about $200,000

Police allege the murder was prompted by a dispute over about $200,000 They haven't ruled out more arrests and allege some involved have links to bikie gangs

Ho Ledinh, 65, was sipping tea with friends at the Happy Cup Cafe at Bankstown City Plaza when he was shot dead in front of horrified families on January 23, 2018.

The married father-of-five died despite frantic attempts from other diners and paramedics to save him.

NSW Police now believe the dispute was over a sum of around $200,000.

Heavily armed officers stormed a home at Leppington this morning, arresting Abraham Sinai, 34, who is accused of hiring a gunman to carry out the hit and enlisting his own wife to help orchestrate the murder.

Mr Sinai was taken to Narellan Police Station, where he was charged with murder.

The father-of-five was sipping tea with friends when he was gunned down. ( Facebook )

Arthur Kelekolio, 38, allegedly pulled the trigger and fired four shots at Ho Ledinh, while Analosa Ah Keni, 35, allegedly provided him with information and offered her van as the getaway car.

In February 2018, Kelekolio was arrested at Sydney International Airport as he was trying to board a flight to Bali, while Ah Keni was arrested a month later.

Both were charged with murder.

A source close to the investigation has told the ABC that detectives are looking at whether "others" hired Mr Sinai to organise the alleged hit on Mr Ho.

NSW Homicide Squad Commander Scott Cook has not ruled out further arrests, and believes some of those responsible for the murder allegedly have links to bikie gangs.

"We believe this dispute was largely over money — hundreds of thousands of dollars," he said.

"I'd particularly like to thank the community of Bankstown — they've stepped up and provided their police with information that's been crucial to this outcome."