Police said that before the incident, Mr Volkov had gone out and returned home around midnight. Not long after, the security guard heard the couple arguing loudly in their room, and then heard something heavy fall to the ground.
He went to check and found Mr Volkov dead on the ground outside, with a broken neck, two broken arms and a broken ankle.
Police believe Mr Volkov either decided to jump off the balcony or accidentally fell down.
Police are interviewing the girlfriend to try and work out what happened.
His body has been taken to Vachira Hospital.