Ching said it was common practice for the company to keep a large amount of cash in the office, as it served as the agent of fashion merchandisers in Nigeria and assisted them in making payments to suppliers in Hong Kong.

She alleged that Mbachu carried out the robbery with a co-culprit who had already pleaded guilty to the offence.

She said the pair - armed with a pistol and knives - initially posed as customers to get inside the building, then forced their way into a room where a business transaction was being processed.

Once inside the room, the prosecutor said, they shouted: 'Robbery!'

They then produced the gun and knives, the court heard.

Ching said they tied up a member of staff and a supplier, covering their eyes and mouths with tape. Two customers outside the room were forced to lie on the floor and hand over their mobile phones.

Having reported the robbery to police, company employees discovered that a total of US$169,433 in cash was missing from the safe, along with a laptop computer and the two mobile phones.

But a closed-circuit television system installed in the building captured images of the robbers, and several Nigerians working in the area came forward and offered their help in finding the perpetrators.

As a result, on November 1, Mbachu and his partner were found at a guest house in Yuen Long.

The court heard that Mbachu, who pleaded not guilty to the offence yesterday, came to Hong Kong in 2007 as a visitor.

The case continues today before Deputy High Court Judge Colin Mackintosh.