Police are looking for a chubby man in his 50s who posed as a male modelling agent on the northern beaches and convinced a 19-year-old man to strip for him during an audition.

The scout interviewed the eager teen - whom he met in Manly - over an eight-hour period, which included taking him to a bar and a restaurant and having his measurements taken.

But police believe it was never the intention of the man to hire the applicant as a model.

The "model scout'' first approached the 19-year-old at his workplace in Manly in late April, police said.

He told him he was the owner of a male modelling agency, was interested in the teen, and invited him to come in to his Newport office the next day for an interview.