An off-duty Milwaukee police officer involved in a fight that ended with a 25-year-old man being seriously injured has been arrested.

Michael Mattioli, 32, was booked into Milwaukee County Jail Sunday evening on unspecified charges, according to online records.

On Sunday morning, crime scene tape cordoned off a house owned by Mattioli, who has worked for the department since 2006, according to city property and employment records.

The Milwaukee Police Department confirmed officers responded to the 4500 block of West Cleveland Avenue about 7:40 a.m. Sunday for a battery complaint.

The injured man was not responsive at the scene; the off-duty officer and man knew each other, the department said in a news release. The off-duty officer was not injured.

The incident is being investigated by the Milwaukee County District Attorney’s Office, police said.

Milwaukee Police Chief Alfonso Morales and several other officers were at the scene, where the department had set up a command post.

The department did not identify the officer by name in the release, saying he is a 32-year-old man with more than 13 years of service and had been placed on administrative duty.

The Milwaukee Fire Department took the injured man by ambulance to St. Luke's Medical Center, according to Deputy Chief Joseph Hegeman. He did not identify the man and did not give his condition.

The man was a guest at a party thrown by Mattioli where a fight broke out, several sources told the Journal Sentinel.

The state currently is under a stay-at-home order during the coronavirus pandemic — meaning large groups are not supposed to congregate in an effort to stop the virus' spread — and local police agencies, including the Milwaukee Police Department, have been enforcing the order.

Contact Gina Barton at (414) 224-2125 or gbarton@gannett.com. Follow her on Twitter at @writerbarton.