Peru's jailed ex-president Alberto Fujimori, 79, has been taken back to prison following his discharge from a clinic after receiving treatment for a heart ailment, his doctor said Monday.

Alejandro Aguinaga said Fujimori had been discharged from the clinic on Saturday evening after five days of treatment for heart palpitations.

Aguinaga told Canal N television that Fujimori will from now on have a device in prison which will allow him to monitor his heart rate.

Fujimori, who is serving a 25-year sentence for human rights abuses and corruption, collapsed in prison in Lima last Tuesday and was rushed to the clinic. He was treated in intensive care for 72 hours.

It was the second time in three months that Fujimori was hospitalized with a heart problem.

He was convicted in 2007 for his role in killings by a death squad targeting supposed guerrillas when he was in power from 1990-2000.

He has since been in and out of hospital with heart, back and stomach trouble and growths on his tongue, which has been operated on several times for cancer.

The courts have rejected efforts by his family to have him freed from prison.

Last year his daughter Keiko Fujimori narrowly lost a presidential election to Pedro Pablo Kuczynski.

Kuczynski has suggested he might consider a pardon on humanitarian grounds, with several sources indicating he could act before Pope Francis visits Chile and Peru in January.

Source: AFP