Former Malaysian Prime Minister Mahathir Mohamad reacts during a press conference in Kuala Lumpur, Malaysia, in 2020. (AP)

Former Malaysian Prime Minister Mahathir Mohamad was released from a specialized heart hospital on Friday, following a four-day medical examination.

The 98-year-old prominent political figure in Malaysia had served as prime minister twice, totaling 24 years in office. He had been admitted to the National Heart Institute in Kuala Lumpur on Tuesday for observation, as reported by an anonymous aide close to him.

"Yes, Mahathir has been discharged from the hospital," they said on Friday, without giving further details. Another official close to Mahathir said on Thursday that the former leader was "being treated for an infection."

In recent years, Mahathir Mohamad has faced multiple heart-related issues, including at least two heart attacks and undergoing two bypass surgeries. He was admitted to the hospital in December 2021 and January 2022 for medical evaluations.

Having served as Malaysia's leader from 1981 to 2003, Mahathir made a remarkable comeback at the age of 92 in 2018, leading a reformist coalition. However, the administration faced internal conflicts, resulting in its collapse in 2020.

In the 2022 general election, Mahathir was defeated, but he joined forces with ethnic Malay political parties in an effort to overthrow the current government, headed by Prime Minister Anwar Ibrahim.