Police hope a woman can shed light on the suspicious death of a man who fell from a high-rise building in Cairns, far north Queensland

The 51-year-old fell from an upper floor of the Wharf Street building about 6.20am on Saturday.

On Monday, police released grainy security camera footage of a woman who had spoken to him about two hours earlier.

"We are very keen to try and work out who she is," a police spokesman said.

Officers have been retracing the man's final movements and hope the woman, or anyone who can identify her, will come forward.

The woman was wearing a black and white stripe top, black three-quarter length pants, and a black hat.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.