Police arrested a 76-year-old former top bureaucrat of the farm ministry on Saturday over the alleged murder of his son at their home in Tokyo.

Hideaki Kumazawa, also a former Japanese ambassador to the Czech Republic, was arrested at the scene after the police received a call from him saying he had stabbed his son to death, according to investigators. His 44-year-old son Eiichiro was confirmed dead after being taken to a hospital.

Kumazawa has admitted to stabbing his son with a kitchen knife, according to the police. He is believed to have lived with his wife and son.

After arriving at the scene, a police officer found the collapsed victim bleeding from the chest.

Kumazawa, a graduate of the University of Tokyo who joined the predecessor of the Ministry of Agriculture, Farm, Forestry and Fisheries in 1967, became the ministry's top bureaucrat in 2001.

He stepped down the following year amid criticism of the ministry's handling of a mad cow disease outbreak.

He served as Japan's ambassador to the Czech Republic from 2005 to 2008.