Latin America's top human rights court has upheld the conviction in Peru of a US citizen, Lori Berenson, on terrorism charges.
Berenson says she is innocent
The Inter-American Court of Human Rights ruled that Berenson's 20-year prison term still stood, Peru's President Alejandro Toledo said.
The decision means the 35-year-old American will remain in prison until a fortnight after her 46th birthday.
Berenson was convicted for assisting rebels. She maintains her innocence.
She had asked the Costa Rica-based Inter-American Court of Human Rights to overturn her conviction, with her legal team arguing she was not given a fair trial in Peru.
Many Peruvians consider her a terrorist and President Toledo welcomed the court's decision.
BERENSON CASE DATES
1996: First trial, jailed for life
2000: Conviction overturned, civil retrial ordered
June 2001: Convicted and sentenced to 20 years
February 2002: Supreme Court upholds sentence
"This undoubtedly brings great satisfaction and tranquillity to the Peruvian justice system and to all Peruvians," he told Peruvian radio.
Peru's constitutional court declared the country's anti-terrorism laws illegal last year, paving the way for retrials for more than 2,000 convicted left-wing rebels.
Ever since then, President Toledo - South America's least popular leader - has been under enormous pressure to show that he is tough on terror, says the BBC's South America correspondent Elliott Gotkine.
Berenson was originally arrested in 1995 and sentenced to life behind bars by a military tribunal the following year.
That sentence was reduced to 20 years by a civil court in 2001.
The court found her guilty of collaborating with the left-wing Tupac Amaru rebel group in a 1995 plot to attack Peru's congress.
Berenson has previously ruled out serving her sentence in a US jail, because she claims she is innocent.