LIMA - Peruvian President Pedro Pablo Kuczynski pardoned former authoritarian leader Alberto Fujimori late on Sunday, clearing him of convictions for human rights crimes and graft before completion of a 25-year prison sentence.

The decision stunned many in Peru and will likely rile large swaths of Peruvian society, possibly prompting resignations from the Cabinet. One ruling lawmaker, Alberto de Belaunde, announced on Twitter that he was breaking from Kuczynski's party.

Kuczynski's office said in a statement that a medical review showed Fujimori, who governed Peru from 1990 to 2000, suffered from "a progressive, degenerative and incurable disease."

Fujimori, who like Kuczynski is 79, was rushed to the hospital late on Saturday after suffering a severe drop in blood pressure and abnormal blood pressure that put his life at risk, according to a doctor.

The pardon comes just days after a faction of Fujimori's supporters in the opposition-controlled Congress saved Kuczynski from a motion that would have forced him from office in the wake of a graft scandal.

Fujimori is a deeply divisive figure in Peru. While many consider him a corrupt dictator, others credit him with ending an economic crisis and bloody leftist insurgency during his 1990-2000 term.

The pardon will likely fuel speculation that Kuczynski promised lawmakers to free Fujimori in exchange for help staying in office - an allegation by opposition lawmakers that the government has repeatedly denied.

Before the announcement, Kuczynski summoned his Cabinet and ruling party for an extraordinary meeting on Christmas Eve.

TV images showed Fujimori's supporters cheering the decision outside the hospital in Lima where Fujimori was rushed by ambulance from prison late on Saturday.

Before the pardon was announced, Maria Luisa Cuculiza, a friend and former minister of Fujimori, said Fujimori no longer has any political ambitions.

"He wants to be free. He wants peace and progress for the country. He doesn't want to return to politics. He just wants to be a good grandfather. He just told me that," Cuculiza told Reuters by phone after visiting Fujimori in the hospital.

(Reporting by Mitra Taj and Marco Aquino; Editing by Leslie Adler)