A man has serious leg injuries after a head-on crash in the Auckland suburb of St Heliers.

Two vehicles collided just before 5.30am on St Heliers Bay Rd, near the BNZ bank.

The man was trapped in his car by his legs for a time but he has been freed and has been taken to hospital.

Part of St Heliers Bay Rd, between Benbow and Devore Sts is still closed.