A man arrested by Immigration and Customs Enforcement died in a New York jail on Thursday.

Officials told Newsday that the 42-year-old man’s death in a Nassau County jail is currently under investigation.

“There is an ongoing investigation, which will be thorough and transparent to determine the cause of death,” Nassau County Sheriff Anthony LaRocco said in a statement to Newsday. “Nassau County takes seriously its obligation to treat every prisoner humanely.”

The man, who has not been publicly identified, died roughly 18 hours after arriving at the jail, News 12 Long Island reported. The New York State Attorney General’s Office has also launched an investigation into the death.

At least 12 people have died in ICE custody so far this year. The agency has faced increasing criticism for snatching people off the streets, oftentimes in masks to hide agents’ identities.