Karel Navarro, File, Associated Press
FILE - U.S. political activist Lori Berenson speaks to The Associated Press at her home in Lima, Peru, in this Nov. 9, 2010 file photo. Paroled U.S. activist Lori Berenson was headed for New York early Saturday Dec. 17, 2011 after a Peruvian court ruled she and her toddler son could travel there for the holidays, airport security officials said.

LIMA, Peru — Peru's government abused its authority by barring paroled U.S. activist Lori Berenson and her 31-month-old son from leaving the country to spend the holidays in New York City with her family, her lawyer charged Saturday.

"Administratively, you can't block a court order," Anibal Apari said after Berenson told The Associated Press that she and her son Salvador were prevented from boarding a flight Friday night despite being granted permission in court.

"They didn't let me leave and they're putting out this version that I arrived late," she said in a brief phone conversation.

Local media had initially reported, citing unnamed airport officials, that Berenson arrived late for the flight. But video taken by a local TV channel showed her pacing nervously in front the Continental Airlines ticket counter and talking with an agent more than an hour before the flight left.

"An abuse of authority has been committed," Apari told the AP. Apari, who is Salvador's father but is separated from Berenson, blamed the Interior Ministry directly and said no official explanation had been provided.

He said Berenson presented the document issued by the judiciary authorizing her departure to migration officials at the airport but they demanded an additional document they referred to as "an exit order."

"It doesn't exist. They made it up," he said of the purported document.

The Interior Ministry's communications chief, Zully Bismarck, said she was not immediately able to address the issue when reached by the AP on Saturday afternoon.

Berenson, 42, was paroled last year after serving 15 years for aiding the Tupac Amaru leftist rebel group.

Arrested in 1995, the former Massachusetts Institute of Technology student was accused of helping the rebels plan an armed takeover of Congress, an attack that never happened.

A military court convicted her the following year and sentenced her to life in prison for sedition. After the U.S. government pressured Peruvian officials, she was retried in civil courts in 2001 and sentenced to 20 years for terrorist collaboration.

A three-judge appeals court had given her permission to leave the country beginning Friday with the stipulation she return by Jan. 11.

The panel had overturned a lower-court judge's initial refusal in October.

Peru's anti-terrorism prosecutor, Julio Galindo, told the AP he had asked the appeals court Friday to nullify the decision because it violated a law prohibiting paroled prisoners from leaving the country. He said he didn't know whether the court acted on that appeal and Peru's courts spokesman, Guillermo Gonzalez, said he had no information on the matter.

Asked about Berenson's next step, Apari said she had been told to go to the Interior Ministry on Monday.

Berenson's parents, often outspoken on her behalf, did not respond Saturday to phone calls seeking comment.

Some Peruvians consider Berenson a terrorist and have publicly insulted her on the street.

The prosecutor, Galindo, had opposed letting Berenson out of prison before her 20-year sentence for aiding terrorism ends in 2015, saying it would set a bad precedent for the early release of others convicted of terrorism-related crimes.

Mark Berenson, who turns 70 on Dec. 29, told the AP on Friday that his daughter had every intention of returning to Peru.

"As Lori says, if she doesn't come home, let Interpol arrest her," he said.

Peru could seek her extradition and return her to prison if she doesn't come back in the allotted time, Gonzalez said.

On Saturday, Berenson left her apartment around midday to take Salvador for a walk and did not comment to new crews other than to ask them to leave her in peace.

Her journey from prison inmate to parolee has been anguished, and Peruvian news media have repeatedly hounded and mobbed her and frightened young Salvador, said Mark Berenson.

Last month, a local TV channel obtained Berenson's new address and showed video of her home. Her father complained that the act endangered his daughter and said the U.S. Embassy had complained.

Lori "just wants to be a low-profile person and get on with her life and be a good citizen," Berenson said, adding that he planned to appeal to President Ollanta Humala to send his daughter home.

Humala could by law commute his daughter's sentence but has not indicated whether he might do so.

Unrepentant when arrested, Berenson softened during years of sometimes harsh prison conditions, and was eventually praised as a model prisoner. Since her initial parole in May 2010, Berenson repeatedly expressed regret for aiding the rebel group.

Yet many Peruvians see her as a symbol of the 1980-2000 rebel conflict that claimed some 70,000 lives. The fanatical Maoist Shining Path movement did most of the killing; Tupac Amaru was a lesser player.

Berenson has acknowledged helping the rebels rent a safe house, where authorities seized a cache of weapons. But she insists she didn't know guns were being stored there. She denies ever engaging in violence.

In an interview with the AP last year, Berenson said she was deeply troubled at having become Peru's "face of terrorism" and felt she'd become a politically convenient scapegoat.

Associated Press writer Franklin Briceno contributed to this report.