A Michigan doctor who came to the U.S. from Poland as a young child was in jail Monday, nearly a week after immigration agents arrested him at his home.

It's not clear why Lukasz Niec, 43, was taken into custody last Tuesday. Niec is a legal U.S. resident who works at Bronson Methodist Hospital in Kalamazoo. He has two misdemeanor convictions from high school and an impaired driving conviction from 2008 that was later dismissed.

The Associated Press sent an email Monday seeking comment from Immigration and Customs Enforcement. An automatic response said the agency's public affairs employees aren't working because of the government shutdown.

His wife, Rachelle Burkart-Niec, said he pleaded guilty in high school to malicious destruction of property and receiving stolen goods and was told the convictions wouldn't be used in a deportation. Kalamazoo County court records show he pleaded guilty to an impaired driving offense in 2008. After completing probation, the conviction was set aside and case was dismissed as part of a plea agreement. A jury also acquitted him of a 2013 domestic violence charge, MLive reported.

"He's taken care of the people of the U.S. as a physician, he's taken care of the people of this community," she told MLive. "After all this time, when is somebody finally free?"

Niec came from Poland to the Detroit area when he was about 5 with his parents and sister. He has one daughter and his wife another from previous relationships, and they married in July 2016.

"He cannot go back to Poland, a country he doesn't know, (where) he has no family," his sister, Iwona Niec-Villaire, told WOOD-TV. "Both our parents passed away in the United States. He doesn't know anyone; he wouldn't know where to go."

Bronson Healthcare, which owns the hospital where Niec works, released a statement, saying it "simply does not make sense" to lock up a "skilled and caring physician." Niec has been on the Bronson staff since 2007.