(Reuters) - As many as 600,000 illegal immigrants in several U.S. states could have a path to legally remain in the country, according to an analysis released on Thursday by a legal aid group.

FILE PHOTO: People are taken into custody by the U.S. Border Patrol near Falfurrias, Texas, U.S., on March 29, 2013. REUTERS/Eric Thayer/File Photo

A statistical review of immigrant screenings done by Catholic Legal Immigration Network (CLINIC) determined that around 15 percent of the 4 million illegal immigrants in seven southern U.S. states had grounds to apply for legal status based on fears of persecution in their homeland, family ties or other factors.

The percentage of the 11 million illegal immigrants across the country who might be eligible to stay in the United States could be even higher, according to University of California at San Diego political scientist Tom Wong, who conducted the analysis for CLINIC.

“As we ramp up immigration enforcement in the United States, we should take this figure and remind ourselves that we shouldn’t deport first and then ask questions,” Wong said in a telephone interview.

His analysis supports the contention by immigrant rights groups that with assistance from lawyers, significant numbers of illegal immigrants could be allowed to remain in the United States.

Immigration and Customs Enforcement spokeswoman Danielle Bennett said the agency could delay a deportation if an immigrant has a pending appeal or application for legal status.

“Before carrying out a removal, U.S. Immigration and Customs Enforcement conducts a thorough review of each case to determine whether there are any reasons the removal order issued by the immigration court should not be executed at that time,” she said in an email.

President Donald Trump’s administration has warned that the vast majority of the 11 million illegal immigrants in the United States could be subject to deportation.

CLINIC, one of the largest U.S. providers of legal aid to immigrants, and its affiliates interviewed more than 2,700 immigrants in seven southern states, including Florida, Georgia, Virginia and Texas.

The largest portion of those screened who might attain legal status were those who had a credible fear of persecution in their home country that could form the basis for an asylum claim.

But a majority of applications for U.S. asylum are denied.

Other categories included victims of serious crimes, such as domestic violence or extortion, who cooperated with law enforcement, and immigrants with family ties to U.S. citizens.

“There isn’t a line for a person to get legal status in the country,” said Sarah Pierce, an analyst with the Migration Policy Institute. “There’s a bunch of small pigeon-hole categories. So the first step is to see if someone fits into one of those categories.”