The Trump administration is increasingly cracking down on applications for passports by lifelong US residents who they suspect of being born outside the country, according to attorneys working near the US-Mexico border.

Lawyers for Hispanic Americans living near the border in Texas say their clients are increasingly being denied the documents, because the government suspects their birth certificates were falsified. These denials can put applicant’s entire citizenship status in jeopardy.

“I’ve had probably 20 people who have been sent to the detention centre – US citizens,” attorney Jaime Diez told the Washington Post of clients who had recently applied for passports.

The apparent crackdown stems from an allegation that US government first made in the 1990s, when they claimed midwives in the border region had falsified US birth certificates for children who were actually born in Mexico. Because of this, both the George W Bush and Barack Obama administrations started demanding more information from passport applicants born to midwives in the area.

The practice slowed after 2009, when the government settled a class-action lawsuit with applicants who claimed they had been unfairly denied passports. But it appears to be picking up again now, according to attorneys interviewed by both the Post and The Independent.

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Lisa Brodyaga, one of the attorneys for the plaintiffs in the 2009 case, said she had seen a recent increase in the number of cases, and in the government’s willingness to take them to court. That's made it much harder for her clients – many of whom can’t afford an expensive legal defence – to make their cases.

The State Department denied any change in policy, saying it required additional proof of citizenship from applicants who had both a US and foreign birth certificate, or were born to a midwife “suspected of having engaged in fraudulent activities".

“Individuals who are unable to demonstrate that they were born in the United States are denied issuance of a passport,” the department said.

Melania Trump visits child immigration center in Texas

But more than a change in policy, Ms Brodyaga said, she’s noticed a change in attitude under the Trump administration. The lawyers the government sends in to take depositions, she said, "tend not to believe anyone".

“They think we're all liars, including the lawyers," she added.

Lisa Graybill, another attorney for the plaintiffs in 2009, said the recent reports were disturbing in the light of increased immigration enforcement across the board. She and other attorneys pointed to Mr Trump’s “zero tolerance” immigration policy, his travel ban, and the termination of the DACA programme for young immigrants, as evidence of his administration’s hostility toward immigrants.