Police south of Sydney spent Monday morning on a fishing expedition after a passerby found a flurry of cash floating in a creek near Wollongong.

Nine News reported at least $2000 in $50 notes were found scattered around Mullet Creek in Dapto.

A woman on her way to the train station first noticed the cash about 9.20am and sent a photo to her boyfriend. He then contacted his elderly father, who alerted police.

Responding officers and Fire and Rescue NSW were forced to be creative in their retrieval mission, fishing the notes from the creek with a long-handled net.