Fujimori, 85, is serving a 25-year sentence for human rights abuses and corruption. Earlier this week, Peru's top constitutional court had ruled to restore his pardon, spurring an international court to urge Peru's government to not free him.
The former president, who was in power through the 1990s, received a presidential pardon in 2017. However, pressure from the Inter-American Court of Human Rights (IACHR) has repeatedly snarled his attempts to regain freedom.
Fujimori's lawyer, Elio Riera, said in a radio interview that his legal team was considering all avenues to have the pardon restored.
He was convicted of ordering the massacre of 25 people in 1991 and 1992 while his government was fighting against the Shining Path guerrillas.
Fujimori dissolved Congress in 1992 and stayed in power for nearly a decade.
The government of unpopular President Dina Boluarte, who came into power late last year after then-President Pedro Castillo attempted to dissolve Congress, had initially said it would comply with the pardon.
Fujimori and Castillo are now jailed at the same prison, along with former President Alejandro Toledo, who is accused of receiving millions in bribes from Brazilian construction company Odebrecht.
(Reporting by Marco Aquino and Kylie Madry; Editing by Sarah Morland and Sandra Maler)
By Marco Aquino