A patient crook armed with a fishing rod hooked himself a $700 Versace necklace from a mannequin while standing on the pavement outside a high-end Melbourne boutique.

Police believe the man broke a small hole in the shop window before spending nearly three hours manoeuvring the line to steal the jewellery.

CCTV footage shows the man, who police believe is aged in his 40s or 50s, outside the Little Collins Street store just after 2am on Monday, February 24.

Senior Constable Bede Whitty said the man broke a hole in the glass without being seen by anyone.