The Independent Police Complaints Commission is investigating the police response to a domestic incident in Oldham last month.
Greater Manchester Police officers were sent to a house on Pemberton Way in the early hours of July 25th after reports of concerns for the welfare of a woman.
The police watchdog said officers attended the address to deal with the incident and then returned a short time later when an alleged hostage situation began. This was resolved approximately 26 hours later and the man was arrested.
During the hostage situation, the woman and a child received injuries that required hospital treatment.
The IPCC said it received a referral from GMP the next day regarding the police contact with the woman, and the accused, on the same day the incident began.
The Greater Manchester Police criminal investigation continues.