Former Malaysian prime minister Abdullah Ahmad Badawi died on Monday, aged 85, his family and medical authorities reported.

Abdullah became Malaysia's fifth prime minister in 2003, following the resignation of veteran leader Mahathir Mohamad after 22 years at the helm.

The former premier died at 7.10pm at the National Heart Institute in the capital Kuala Lumpur, his son-in-law and former health minister Khairy Jamaluddin said in an Instagram post, without specifying a cause of death.

Abdullah was admitted to the National Heart Institute on Sunday after experiencing breathing difficulties and was immediately placed under intensive care, the institute said in a statement.

"Despite all medical efforts, he passed away peacefully, surrounded by his loved ones," the institute said.

As premier of the Muslim-majority country, Abdullah embarked on an anti-corruption drive and espoused a moderate version of Islam that aimed for economic and technological progress over religious fundamentalism.

But he came under public criticism for his review of fuel subsidies that saw a sharp spike in prices.

Abdullah stepped down in 2009, a year after an election that saw the then-ruling Barisan Nasional coalition lose its parliamentary supermajority for the first time in the country's history.

He was succeeded by Najib Razak. (Reuters)