KUALA LUMPUR: Former Malaysian Prime Minister Mahathir Mohamad, 96, has been admitted to a hospital and will be undergoing a full medical check up, the hospital said on Thursday.

"He shall be undergoing a full medical check-up and further observation," the National Heart Institute said in a statement.

It did not say why Mahathir was admitted. His spokesman declined further comment.

The former premier is expected to be at the hospital for the next few days, the hospital said.

Mahathir, Malaysia's longest serving prime minister, has a history of heart troubles. He has had heart attacks and bypass surgeries.

The nonagenarian served as prime minister for 22 years until 2003.

He returned as premier at the age of 92 after leading the opposition coalition to a historic win in 2018, defeating the party that he had once led. His government collapsed in less then two years due to infighting.

He remains an influential figure in Malaysian politics.