A cleaner plunged 30 floors to his death down a lift shaft of a Hong Kong office building, a preliminary investigation has suggested.

Firefighters made the grim discovery of the body of the man at the foot of a lift shaft of a commercial building around 6.09pm on Tuesday.

A source familiar with the case said the victim was working with three female cleaners was responsible for the air handling unit and other equipment rooms.

One of the other workers heard the victim scream as they worked on the 30th floor and went to investigate.

Fire Services Department personnel dealt with an industrial accident which claimed the life of a cleaner at an office block in Kwun Tong on Tuesday.

The emergency door of the air handling unit was open and colleagues suspected the man had fallen into the lift shaft at the How Ming Street, Kwun Tong, office block.

The female cleaners alerted the building’s staff, who contacted police.

Senior Station Officer Cheung Chi-kong of the fire service confirmed the cleaner was believed to have fallen down the shaft.

He added preliminary investigations suggested the incident did not involve mechanical problems with the lifts.

Cheung said it took some time for firefighters to clear the scene and the victim’s remains were removed from the lift shaft at around 8pm.

The high angle rescue team from the Fire Services Department, seven fire trucks and three ambulances were involved in the incident.

Cheung said the circumstances of the death would be investigated by the Labour Department and the Electrical and Mechanical Services Department. Specialists from both agencies were also at the scene.