NSW Police are seeking public assistance to find a Pasifika man missing from Sydney's south.

Raymond Robinson, 40, last spoke with an associate at 1pm on Friday, 25 May and has been unreachable since.

Sutherland Police Area Command officers have begun investigating his disappearance.

Concerns for his welfare have been raised as this behaviour is out of character.

Mr Robinson is described as Pacific Islander/Maori in appearance, 175cm tall, with a solid build, dark hair and tribal tattoos on both arms.

The clothing he was wearing before being reported missing is unknown.

Mr Robinson is known to frequent the Sylvania and Richmond areas. Inquiries indicate he may have been in Auburn around 11am on Saturday.

An update reveals that he may have been in the vicinity of Sydney Olympic Park approximately 4:30pm on Saturday.

Members of the public with information about Mr Robinson's whereabouts are urged to contact Crime Stoppers or 1800 333 000.

Information is treated in strict confidence.

The public is reminded not to report information via NSW Police social media pages.