Former Prime Minister P V Narasimha Rao has been admitted to the All India Institute of Medical Sciences for a check-up.

"The former prime minister was admitted three days ago. He is alright," an aide of Rao said.

Prime Minister Dr Manmohan Singh visited him, sources said.

Rao's condition was stable and he was undergoing various tests, doctors at AIIMS said.

Tests had shown rise in liver enzymes and he was shifted to the cardiac ward on Saturday for examination of his heart condition, the doctors said.

Rao, 83, was admitted to the hospital's gastro ward on June 16 after he complained of loss in appetite.