A man arrested by US Customs and Immigration Enforcement (Ice) died in a Long Island, New York, jail on Thursday, according to a report.

Officials in Nassau county confirmed the death of a 42-year-old man to Newsday but declined to share details, saying that an investigation was under way.

“There is an ongoing investigation, which will be thorough and transparent to determine the cause of death,” Nassau county sheriff Anthony LaRocco told the outlet. “Nassau county takes seriously its obligation to treat every prisoner humanely.”

The outlet reported that this is the first death of an Ice detainee in custody in Nassau county, where more than 1,400 people detained by the federal agency have been held between February and June this year.

A spokesperson for the office of the New York state attorney general, Letitia James, confirmed that it is conducting a preliminary assessment of the death.

Police arrived at the Nassau County Correctional Center in East Meadow on Thursday morning at around 6.30am to find the man “not breathing” after he was “observed in his cell unresponsive”.

At least 14 people have died in Ice custody in fiscal year 2025, which began in October 2024, according Ice figures. Around 58,766 people have been detained this year, as of 7 September, according to the Transactional Records Access Clearinghouse.

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Nassau county, home to a large Salvadorian and Guatemalan population, entered into a partnership with Ice in February, allocating 50 local jail cells for Ice detainees. The man who died was being held as part of that partnership.

Nassau county executive Bruce Blakeman said in July that “there is no evidence” to suggest anyone was being held longer than 72 hours, per the agreement with Ice. The official said the federal government was reimbursing the county $195 per Ice detainee, per night.

The publication New York Focus calculates that New York state’s county jails have held six times more people for immigration authorities than they did in 2024.

The state’s jail system booked a total of nearly 2,800 people arrested for immigration reasons in the first seven months of 2025, up from only 500 last year, according to Ice data.