LIMA, Peru — Lori Berenson, the New Yorker paroled last year after serving more than 15 years in prison here on a terrorism conviction, was blocked from leaving the country for what was to have been her first visit home since her arrest, she said Saturday.

A Peruvian court had granted Ms. Berenson permission to visit her family in New York City for the holidays, but when she and her young son arrived at the airport on Friday night, they were turned away by immigration authorities.

“They said I needed a document for immigration and I didn’t have it,” Ms. Berenson said, “so they wouldn’t let me leave the country.”

It was unclear what document the immigration authorities wanted. Ms. Berenson said she had all of the documents required for travel.