The world number one and Federer have long been involved in an epic on-court rivalry, facing each other 50 times since their first head-to-head meeting back in 2006.
Roger Federer and Novak Djokovic have been on-court tennis rivals for the last 15 years
Djokovic's father Srdjan has reportedly launched an astonishing verbal attack on Federer
The 33-year-old's dad, Srdjan, has hit out at Federer while speaking to Serbian TV, saying the tennis legend is 'not such a good man'.
He told K1 as per The Sun: 'About 15 years ago Federer attacked my son when he was still young, he was 18 or 19 years old.
'I knew someone would be there who would be better than him. So I said that [Federer] was a great champion, the best at the time.
'But as much as he is a great champion, Federer is not such a good man.'
Djokovic Snr has accused Federer of attacking his son Novak when he was 18-years-old
Djokovic leads the on-court head-to-head battle with Federer, winning 27 matches against the Swiss ace, who has won 23.
The Serbian leads 13-6 in all finals and 11-6 in Grand Slam matches alone.
Srdjan also told the Serbian TV channel that his son is a 'great champion the world will never see again'.
He added: 'It is obvious that foreign media outlets do not have the best opinion of us and think that we are constantly bothering them.
Djokovic, now 33, has faced Federer 50 times and has two less Grand Slam titles than his rival
'To tell you the truth, I do not want to be part of your twisted world. I'm sorry you don't like Novak. I just tell you the truth. What should I do?
'They defame him so much and say so many disgusting things about him that it is unbelievable.
'My answers are much clearer compared to how they treat this great champion, that they won't have again in this world.'