NAIROBI (AFP) – Olympic marathon champion Sammy Wanjiru of Kenya died overnight at the age of 24 after falling from the second floor of his home in the town of Nyahururu, police said on Monday.

"He fell from the balcony of his home after a row with his wife. We found him lying on the verandah with a broken skull," a police officer in the region, Jasper Ombati, said.

He added that police were investigation whether Wanjiru had committed suicide or whether he had jumped from the balcony and died accidentally.

Wanjiru made history at the 2008 Beijing Olympics when his winning time of 2 hours 6 minutes 32 seconds destroyed the 24-year-old Olympic record of 2:09:21 set in 1984 by Carlos Lopes of Portugal. It gave Kenya its first Olympic marathon gold.

After Beijing, Wanjiru won the London marathon in 2009 and Chicago in 2009 and 2010.

Wanjiru started his running career young, leaving for Japan in his mid-teens after winning a scholarship for Sendai High School. He became immensely popular in what was for a while his country of adoption.

Over the past several months however, Wanjiru, who leaves behind one daughter, appeared to have entered a downhill spiral, making headlines more for his marital problems and court appearances than for his sporting achievements.

He was involved in a serious car crash in January and was scheduled to re-appear before a Nyahururu court next Monday, accused of being in possession of an unlicensed firearm.

He had earlier been charged with threatening to kill his wife but she subsequently withdrew the charges.

"The theory we are getting from his wife and a watchman is that he came home drunk from the bar and he was accompanied by a woman. When his wife asked why he came home with a woman, an argument ensued, and that is when he fell off the balcony and died," police officer Ombati said.

"He was pronounced dead at the Nyahururu district hospital," he added.

"There is also another theory that during the argument, the wife ran away from their bedroom and her husband ran after her, she locked the stair-case door prompting Wanjiru to look for an alternative way out ... and that is when he jumped off the balcony to the ground and died," he said.

"These are the two theories we are investigating, we cannot conclusively say he committed suicide, or that he jumped down and died accidentally.

"All these are conclusions we will make once the investigation is completed.

"For now we are going on with the investigation, Wanjiru?s wife has recorded a statement with us and their watchman as well. The woman Wanjiru went home with is at the station with us, assisting detectives with the investigation."

In the history of Olympic marathon running, Wanjiru at 21 ranks as the second-youngest winner ever, after the Argentine Juan Carlos Zabala who won at the age of 20 in Los Angeles in 1932.