A man will remain behind bars following a violent domestic incident in Sydney’s south-west, which left a woman critically injured.

20-year-old Akaash Narayan arrested after police were called to a home at Bonnyrigg Heights on Christmas evening, where they found a woman seriously injured.

Narayan allegedly shot his mother-in-law in the head with a nail gun.

The 50-year-old was treated at the scene then taken to hospital for surgery where she remains in a critical condition.

Narayan fled the scene but was later located near the home and taken to Fairfield Police Station.

His bail has been refused with the case adjourned to March.