Man's arm slashed at Sydney park party

A Sydney party-goer's arm has been slashed with a broken bottle, severing an artery.

Officers say they were called to Lackey Street in South Granville about 3.45am (AEDT) on Sunday after a fight broke out, and found the 20-year-old Fairfield man with a deep laceration to his left bicep.

The man had surgery in Westmead Hospital, according to police.

Another man, a 20-year-old from Parramatta, was arrested and questioned but released without charge pending further investigation.

Detectives from Rosehill Local Area Command are waiting to speak with the injured man and have appealed for anyone with information to come forward.