Ms. Morales’s journey from cultivating corn in rural Guatemala to fluffing pillows at an exclusive golf resort took her from the southwest border, where she said she crossed illegally in 1999, to the horse country of New Jersey, where she was hired at the Trump property in 2013 with documents she said were phony.

She said she was not the only worker at the club who was in the country illegally.

Sandra Diaz, 46, a native of Costa Rica who is now a legal resident of the United States, said she, too, was undocumented when she worked at Bedminster between 2010 and 2013. The two women said they worked for years as part of a group of housekeeping, maintenance and landscaping employees at the golf club that included a number of undocumented workers, though they could not say precisely how many. There is no evidence that Mr. Trump or Trump Organization executives knew of their immigration status. But at least two supervisors at the club were aware of it, the women said, and took steps to help workers evade detection and keep their jobs.

“There are many people without papers,” said Ms. Diaz, who said she witnessed several people being hired whom she knew to be undocumented.