Nigeria's President Umaru Yar'Adua attends a Muslim prayer session in Abuja in this September 29, 2009 file photo. [Agencies]

The President died at about 9 p.m. local time (2000 GMT) in his official residence where he was recuperating from his illness, Adeniyi said.

Yar'adua's aides have briefed Acting President" Goodluck Jonathan on the former ruler's transition.

He interrupted his presidential election campaign months later to seek medical care in Germany.

On November 23, 2009, he was flown to Saudi Arabia where he spent three months for the treatment of acute pericarditis, an inflammation of the sac surrounding the heart.

He had not been seen in public since.

Born in northern Nigeria's Katsina State in August 1951, Yar'Adua was a devout Muslim who hailed from a distinguished political family.

His father was a minister in the first post-independence cabinet and his elder brother, Shehu, was number two in the military government of Gen. Olusegun Obasanjo from 1976 to 1979.

He was educated at the Ahmadu Bello University, Zaria, where he obtained a B.Sc in Education/Chemistry in 1975.

He returned to the same university in 1978 and bagged his M.Sc in Analytical Chemistry in 1980.

Yar'Adua began his professional life as a chemistry teacher before going into business in the 1980s, starting at Sambo Farms Ltd in Funtua, Katsina State, as its General Manager between 1983 and 1989.

At the inception of the transitional government of Gen. Abdulsalam Abubakar in 1998, Yar'Adua founded the K34 political association which later helped to form the ruling People's Democratic Party (PDP).

He contested and won election as Governor of Katsina State in 1999 and was re-elected in 2003.

He became the first governor to publicly declare his assets and promised to do the same again at the end of his tenure.

In 2007, Yar'Adua was elected Nigeria's first university-educated President.

He is survived by an aged mother, wife, and seven children.