Immigration officials are reviewing whether a 19-year-old man deported last week from South Texas is actually a U.S. citizen born in Houston.

Luis Alberto Delgado said he and his older brother were stopped last Thursday by a Jim Wells County Sheriff captain, who called the U.S. Border Patrol.

Despite carrying a birth certificate showing he was born at Houston's Ben Taub Hospital, a state of Texas ID card and a Social Security card, Delgado said he was taken into Border Patrol custody, questioned for eight hours and pressured into signing paperwork that cleared the way for his removal to Mexico.

Delgado, who returned to Houston three years ago after spending much of his childhood in Mexico, said immigration officials were suspicious because he spoke very little English. He said they kept saying, "No, these papers aren't yours."

"What they did to me was discrimination," Delgado said in a telephone interview from Reynosa. "I don't understand why they did this."

"I am an American citizen," he said.

A U.S. Border Patrol spokesman said that officials do not comment on individual cases. A spokesman for the Texas Department of State Health Services, Chris Van Deusen, confirmed that the state has a birth certificate on file matching the information on one provided to authorities by Delgado. The Houston Chronicle reviewed a certified copy of the birth certificate.

U.S. immigration officials have faced scrutiny in recent years over allegations that they have deported U.S. citizens, including a high-profile case of a mentally disabled Los Angeles man who was lost for months in Mexico in 2007. Rep. Zoe Lofgren, D-Calif., said some cases in the past have been "appalling," but she was encouraged that Immigration and Customs Enforcement Assistant Secretary John Morton has taken steps to help revise guidelines to prevent such situations.

Isaias Torres, a Houston immigration attorney who took Delgado's case pro bono, said he contacted immigration officials Monday and said they initially were responsive to concerns that Delgado is a citizen but have not taken steps to return him to the U.S.

"I hope they will move on this quickly," he said. "We want him back here."

Stopped by a sheriff

Delgado and his brother, Eduardo Luis Pompa, dropped their niece off in Falfurrias last Thursday afternoon and were about 5 miles outside of Alice when they were stopped by a county sheriff.

Capt. Joe R. Martinez said he pulled Pompa over because the passenger, Delgado, was not wearing a seat belt. Martinez said he asked Pompa for a driver's license, but he did not have one. He also did not speak English, Martinez said.

Martinez said he asked the Border Patrol for help to identify the brothers.

Martinez said he booked Pompa into the county jail for driving without a license, and the Border Patrol took Delgado into immigration custody. Martinez said Pompa was released from jail after posting bail after jailers were told by federal officials that he is a U.S. citizen.

In the meantime, Delgado was at a South Texas Border Patrol station being questioned by immigration agents about his papers.

He said he was detained from 4 p.m. to midnight and pressured to sign paperwork that resulted in his being sent to Matamoros.

"The official that was holding me told me I had to sign them … or I would have to stay there," Delgado said.

"I thought if I signed them, they'd let me go free, and I could return to Houston," he said.

Stranded in Reynosa

Delgado said he never was expressly told by the agent that he would be released from custody in the U.S. if he signed the papers, but he believed that to be true.

Torres said Delgado's case may have been complicated for the Border Patrol because Delgado's family used a fake Mexican birth certificate to enroll him in school in Mexico.

He said school officials in Mexico historically give parents of U.S. children a hard time enrolling them in school without a Mexican birth certificate and look the other way if it's fraudulent.

Still, Torres questioned why Delgado was allowed to pass through the port of entry in Laredo three years ago without incident and why immigration officials didn't take more time to verify all of his documents. He said Delgado simply didn't know any better than to sign the immigration paperwork last week, Torres said.

"He's just a teenager," Torres said.

When Delgado tried to come back to the U.S. through the port of entry, he said he was told he could face up to 20 years in prison for entering the country after being deported.

Now, Delgado said, he is stranded in Reynosa, trying to understand how he ended up barred from the U.S.

susan.carroll@chron.com