An undocumented immigrant mother from Honduras said federal officials took her daughter away from her while she was breastfeeding in a detention center, an extreme example of the new US policy that separates families who cross the border illegally.

CNN first reported the incident, which was described by Natalia Cornelio, an attorney with the Texas Civil Rights Project, who interviewed the woman. Cornelio told CNN the woman was placed in handcuffs after she resisted.

US Customs and Border Protection rejected the report. “Nothing could be further from the truth and these allegations are unsubstantiated,” Dan Hetlage, the director of media relations for US Customs and Border Protection, said in a statement.

The Honduran woman, who was not named, was reportedly being prosecuted for crossing the border illegally, part of the US government’s stepped-up immigration enforcement. As Vox’s Dara Lind explained, there’s no explicit US policy to separate undocumented families. But the US government is referring all those who cross the border illegally, even asylum seekers, for criminal prosecution, which means minor children have to be separated from their parents:

Typically, people apprehended crossing into the US are held in immigration detention and sent before an immigration judge to see if they will be deported as unauthorized immigrants. But migrants who’ve been referred for criminal prosecution get sent to a federal jail and brought before a federal judge a few weeks later to see if they’ll get prison time. That’s where the separation happens — because you can’t be kept with your children in federal jail.

The separations are not necessarily permanent, but the incident CNN reported is among the more dramatic anecdotes that have cropped up in recent weeks as the Trump administration announced its new policy, intended to deter illegal crossings. A Honduran father killed himself in detention after being separated from his family; the Boston Globe reported that authorities were telling detained parents they were taking their children for a bath, but their kids were never returned to them.

What some opponents see as a draconian enforcement policy has sparked protests, including one Wednesday that featured Democratic lawmakers.

Ok. Plans have changed again. Now House Dems and activists have linked arms in the street. pic.twitter.com/xBZkwqANM9 — Ella Nilsen (@ella_nilsen) June 13, 2018

The number of families divided as a result of Trump’s policy is still murky. The Intercept reported that “658 children with 638 adults” were placed “in the prosecution process” in the two weeks after Attorney General Jeff Sessions announced the policy on May 7, according to statistics that Customs and Border Protection gave Congress.

This is not an entirely new phenomenon. A New York Times report in April suggested about 700 kids had been split from their parents since October 2017.

Update: This post has been updated to include a statement from US Customs and Border Protection.