Japan's 78-year-old Emperor Akihito has been admitted to University of Tokyo Hospital for tests, the Imperial Household Agency confirmed on Saturday.

The ageing emperor, who has been suffering from several health problems for the last few years, underwent a heart examination after doctors detected symptoms of deficient blood supply to his heart.

He also underwent an hour-long scanning of his coronary arteries at the hospital.

Emperor Akihito cut back on his public duties in the recent years after suffering several health problems such as pneumonia and prostate cancer.

Last year, the emperor had to undergo an angiogram at the same hospital after doctors found his arteries were shrinking. In November, an attack of pneumonia forced him spent 19 days in the hospital.

In 2003, he underwent a surgery for prostate cancer.

Akihito was ascended to the throne in 1989, after the death of his father Hirohito.

The throne of emperor in Japan lost its quasi-divine standing in the aftermath of Second World War, but it is still held in deep respect by majority of the public.