DENVER — Denver officials on Thursday said they would not hand over information requested by U.S. Customs and Immigration Enforcement (ICE) on four men wanted for deportation, the AP reports. 

ICE earlier this week subpoenaed Denver law enforcement for information on four foreign nationals wanted for deportation.

Alethea Smock, public affairs officer for ICE, said Enforcement and Removal Operations issued several immigration subpoenas to the Denver Justice Center requesting information on undocumented immigrants whom ICE seeks additional information for immigration enforcement purposes.

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It's an escalation of the conflict between federal officials and so-called sanctuary cities like Denver. And if city officials don't respond, ICE, the Homeland Security agency responsible for arresting and deporting people in the U.S. illegally, could take the subpoena to a federal judge who can order compliance, and find them in contempt.

The City Attorney's Office said ICE officials did contact the city to request jail release notifications involving four inmates. 

"Contrary to what ICE is saying, we honored three of those requests for the three inmates released at that time," Ryan S. Luby, the city attorney's office public information officer said in an email earlier this week. "We will honor the request for the fourth inmate when he is released."

It's unclear why Denver officials are now withholding information. 

"Denver subsequently received administrative subpoenas from ICE requesting additional information about the four inmates. The subpoenas were not issued by a court of law and not signed by a judge," Luby said in the email. "There is no indication they are related to a criminal investigation. Denver does not comply with subpoenas unless they are Court-ordered or unless they are primarily related to a criminal investigation. Our immigration ordinance fully complies with federal law,” he said. 

Smock said although ICE has not historically had a need to issue immigration subpoenas requesting information, the authority to issue immigration subpoenas is codified in federal law. 

The majority of law enforcement agencies throughout the country willingly cooperate with ICE to provide information regarding undocumented immigrants arrested for crimes in the interest of public safety, she said. ICE is using every tool available to obtain information on release dates or the whereabouts of undocumented immigrants in jurisdictions that chose to, or are unable to, cooperate with ICE.

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