COLUMBUS, Ohio (WSPD) -- The American Civil Liberties Union of Ohio has sent letters to seven county sheriffs in Ohio asking them to ignore requests from the federal government to hold illegal immigrants until they can respond. The requests usually come from U.S. Immigration and Customs Enforcement, but the ACLU says they're unconstitutional.

"ICE detainers are not legally binding if they're not accompanied with probable cause or a warrant. They're merely requests," said Shakyra Diaz with the ACLU of Ohio.

Diaz says many sheriffs across the country are ignoring the requests from ICE because they are liable for holding people in jail longer than usual.

The letters went to sheriff's offices in Butler, Clark, Cuyahoga, Franklin, Mahoning, Montgomery, and Warren counties.

"Those were the counties that had the highest amount of ICE detainer holds," said Diaz.

Hamilton County also has a high number of the requests, but changes are already being considered, so the ACLU didn't decide to write them a letter. 

In most cases, the person being requested to be held has already been released on bond or they've had the criminal charges dismissed. Diaz says it's then that the requests come to allow ICE more time to determine if the person is in the country illegally.

"You need probable cause first and then you can hold someone. You can't hold them first and then try to build up on the probable cause after the fact," said Diaz.

The ACLU says ICE detainer requests have gone out to at least 126 prisons or jails in the state.

The cases typically involve an individual who has either been released on bond or had criminal charges dismissed. In such cases, ICE officials will ask jails to continue to hold individuals, suspected of being here illegally, while the agency determines if they’re ready to take custody over the issue.

ICE spokesman Khaalid Walls released a statement saying the hold requests are simply to have local law enforcement agencies notify them before they release the person and to maintain custody of them for no more than 48 hours, excluding weekends and holidays. He says it's an effort to allow ICE to assume custody of the suspect.

"When law enforcement agencies turn criminals over to ICE rather than releasing them into the community, in enhances public safety and the safety of law enforcement. To further this shared goal, ICE anticipates that law enforcement agencies will comply with immigration detainers," he said.

Recent federal court rulings on the issue have the ACLU warning that complying with the requests could open counties up to lawsuits.

"Sheriff's don't want to be in a position where they are illegally holding someone in jail," Diaz said.

She says they'll keep an eye on the issue and be following up.