The wife of an active-duty Coast Guardsman was arrested earlier this week by federal immigration authorities inside the family residential section of the U.S. Naval Air Station at Key West, Florida, after she was flagged in a routine security check, officials said Saturday.

According to a U.S. official, the woman’s work visa expired around 2017, and she was marked for removal from the United States a few years later. She and the Coast Guardsman were married early this year, said the official, who spoke on condition of anonymity to discuss an enforcement incident.

The official said that when the woman and her Coast Guard husband were preparing to move into their on-base housing on Wednesday, they went to the visitor control center to get a pass so she could access the Key West installation. During the routine security screening required for base access, the woman’s name was flagged as a problem.

Base personnel contacted the Naval Criminal Investigative Service, which looked into the matter, said the official. NCIS and Coast Guard security personnel got permission from the base commander to enter the installation and then went to the Coast Guardsman’s home on Thursday, the official said. They were joined by personnel from Homeland Security Investigations, a unit within Immigration and Customs Enforcement.

HSI eventually took the spouse into custody, and the official said they believe she is still being detained. Officials did not provide the name of the country she is from.