BELGRADE, Serbia — The grandfather of Jelena Djokovic, the wife of Novak Djokovic, has been found tied up in a field after unknown assailants broke into his house in central Serbia.

Djokovic’s press team says in a statement on Thursday the family is in “complete shock over what happened” to 85-year-old Miloslav Radisavljevic.

They say attackers broke into Radisavljevic’s house, kidnapped him, and took him to a field several kilometers away.

Police said, without identifying Radisavljevic, they found a man early Thursday tied to a power pole close to his house in Ljig, some 50 kilometers south of Belgrade.

The man told the police he was also robbed by the two masked assailants of about 220 euros ($260) and a cellphone. Police say the man had no visible injuries.