Tennis player Jelena Dokic’s father has launched a hunger strike to protest against his 15-month jail sentence for threatening Australia’s ambassador to Serbia.

Damir Dokic’s lawyer Bosiljka Djukic said she had been informed that her client was no longer taking any food, water or medicines in prison.

Dokic, 50, is serving his sentence in the northern Serbia town of Sremska Mitrovica.

He was arrested in May after reportedly saying he would blow up Australian ambassador Claire Birgin’s car.

The threat followed negative articles in the Australian press in which Jelena Dokic accused her father of beating her.

Upon arrest, police also found a large number of weapons in Dokic’s home.

He had threatened to fire a rocket launcher at Ms Birgin’s car but later said the statements were made in anger.

The father, who has admitted beating his daughter, was charged with “endangering the security” of the Australian ambassador and unlawful possession of weapons.

His 15-month sentence was confirmed in a retrial.

More In: Tennis | Sport