A man has died after falling from a balcony while speaking to police.

The 55-year-old was seen straddling a railing on the balcony in an apartment complex on Hamilton Road in Fairfield, southwest Sydney, about 2.10am.

Police had been called to the unit after a female resident reported a “domestic and family violence-related incident,” police said.

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Officers on the ground were speaking with the man when he fell as other officers entered the unit.

He was treated for critical head injuries but was pronounced dead at the scene.

A 46-year-old woman inside the unit was assessed by paramedics for “shock and minor injuries,” police said.

Police have launched an investigation into the incident overseen by the Law Enforcement Conduct Commission.

The investigation will also be independently reviewed by the Professional Standards Command.

Anyone with information has been urged to contact Crime Stoppers.

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondblue on 1300224636 or talk to your GP, local health professional or someone you trust.

If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au.