A local man said he was locked up for three days on an immigration detainer, even though he is a U.S. citizen.

Now, the American Civil Liberties Union is suing on behalf of Ernesto Galarza, saying the city of Allentown, Lehigh County, and federal officials violated the man's civil rights.

"We have to find a way to protect American citizens from being wrongfully jailed by the immigration authorities," said attorney David Vaida.

Vaida brought Galarza's case to the attention of the ACLU, which said Galarza, 36, was locked up in Lehigh County Prison for three days on an immigration detainer, even though Galarza was born in New Jersey and is a U.S. citizen of Puerto Rican decent.

"There's no way, by looking at someone, to know whether or not they're American citizens," said Vaida.

The ACLU filed a lawsuit on Galarza's behalf in federal court in Allentown on November 19.

"We need to be very careful not to be so aggressive in enforcing immigration laws so that we violate people's rights the way that Mr. Galarza's were violated," said ACLU spokesperson Valerie Burch.

The ACLU said Allentown police mistakenly picked up Galarza during a drug sweep on November 20, 2008. He was later acquitted of the charges.

The ACLU said police targeted Galarza's boss, a construction contractor from the Dominican Republic.

According to the lawsuit, Galarza posted bail the next day, but Immigration and Customs Enforcement placed him on a detainer.

ICE claimed he was from the Dominican Republic and in the U.S. illegally.

The ACLU said Galarza's Social Security card and Pennsylvania driver's license were in his wallet the whole time.

According to the lawsuit, Galarza was not told why he was being held for nearly three days.

"I was born in New Jersey and I'm a proud American," Galarza said in a statement. "This isn't how Americans should be treated. It's like getting slapped in the face."

Meantime, ICE and the solicitor for Lehigh County have not returned our phone calls seeking comment.

The Allentown solicitor said, "The city received the lawsuit late yesterday [Wednesday] and it's being reviewed."