LIMA, Peru (AP) -- An American woman serving a life sentence for treason in Peru could receive a new trial if fresh evidence is presented in her case, Peru's justice minister has said.

Lawyers for Lori Berenson must present the evidence to Peru's military justice council, which would determine whether to grant a new trial and whether the trial should be held in a military or civilian court, Justice Minister Alfredo Quispe said Friday.

But Grimaldo Achahui, Berenson's attorney, said producing new evidence will be very difficult, since he has not had access to the case's documents and evidence for several months.

Berenson, 28, a New York native and former Massachusetts Institute of Technology student, was sentenced by a secret military court in 1996 for helping leftist Tupac Amaru Revolutionary Movement rebels plan a thwarted attack on Peru's Congress.

Her family and U.S. officials have called for an open, civilian trial for Berenson, arguing that she was denied due process and has not been proven guilty.

U.S. Ambassador Dennis Jett says the case has affected Peru's image abroad.

"Our position is that Berenson should receive a new, civilian trial and that we should continue discussing her case so that it can be resolved in a manner acceptable to both countries," he said.

Berenson's hopes for release were raised in late June when Peru's new Prime Minister, Javier Valle Riestra, said she should be pardoned and sent back to the United States because of flaws in her trial.

But President Alberto Fujimori ruled out a pardon and said the military trial had been fair.