SEATTLE (AP) — A naturalized U.S. citizen from Mexico is suing U.S. Immigration and Customs Enforcement, saying the agency held him in detention for a week even though he had his passport with him and repeatedly insisted he was an American.

The Northwest Immigrant Rights Project filed the lawsuit Friday in U.S. District Court on behalf of Everett resident Carlos Rios, identified as a native of Mexicali, Mexico, who has been in the U.S. since the 1980s and became a citizen in 2000.

“I cannot understand why I was detained and why no one listened to me,” Rios said in a news release issued by the immigrant rights group. “I had my U.S. passport with me when I was detained, and I told this to the immigration officers many times. I hope that this lawsuit can make a difference to ensure that others are not subjected to such terrible, unlawful treatment by U.S. immigration officials.”

The lawsuit says Rios was pulled over on his motorcycle in Pierce County in November 2019 on suspicion of driving under the influence. When he was released from jail the next day, two ICE officers were waiting for him.

Without identifying themselves, they seized him and brought him to the privately run, for-profit Northwest immigration detention center in Tacoma, the lawsuit said.

Rios said he repeatedly asked officials and guards to examine his passport, which was among the belongings that had been seized from him. It wasn't until a week later that he was transported to an ICE office in Tukwila, where ICE officials took his biometric information, reviewed his records and realized he was an American.

That's when he was finally released, the lawsuit said.

The agency did not immediately respond to an email seeking comment Friday.

According to the lawsuit, Rios was subjected to isolation and guards threatened to sedate him. He had to pay $700 to retrieve his motorcycle due to how long it had been impounded, and while in detention he lost the opportunity to begin working at a new welding job.

He now works as a welder at the Port of Everett.

“Despite being a U.S. citizen, ICE deprived him of his liberty for a week, violating his sense of safety and belonging in this country, effectively demonstrating that he was not a full class citizen,” the lawsuit said. “Indeed, the individuals detaining Mr. Rios ignored his pleas that he was a U.S. citizen, and he was left to wonder and despair about what would happen to him.”

The lawsuit seeks damages for false arrest, false imprisonment, negligence and other claims.