A man has died during a police welfare check in Sydney‘s inner south, prompting a critical incident investigation.

Police and paramedics were called to a unit complex on Pitt St in Waterloo just after 2am on Tuesday after receiving a concern for welfare report.

Emergency services found a 45-year-old man at the property and when they attempted to sedate him he fell unconscious.

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Officers and paramedics attempted to revive the man, but he was taken to Royal Prince Alfred Hospital where he was pronounced dead.

A critical incident team will investigate the man’s death.

“The investigation will be (the) subject of an independent review by the Professional Standards Command and oversight by the Law Enforcement Conduct Commission,” NSW Police said.

A report will be prepared for the coroner.

Anyone with any information about the incident has been urged to contact Crime Stoppers.