Attacker 'with a limp' threatens to kill teen girl in Melbourne

A man with a limp and a raspy voice grabbed and threatened to kill a Melbourne girl in a brazen day time attack.

Police have released a digital image of the man they want to speak to over the assault of the 17-year-old in Mill Park on March 23.

It's believed the teen was walking home from school along the bike path in Border Drive when a man began following her about 4.30pm.

When she reached parklands, he grabbed her from behind, covered her mouth and told her to be quiet.

The girl struggled and the man, believed to be in his 50s, threatened to kill her if she did not stay quiet, but she managed to yell and the man fled.

The man has been described as being in his early 50s, Caucasian, has light brown hair and is very tall.

Police believe the attack is a one-off and said no similar incidents have been reported to police. 

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