Bernard Tomic allegedly changes his story while testifying in a Madrid court as to whether his father head-butted his hitting partner outside a hotel in Spain last May.

John Tomic, Bernard's father and coach, is charged with  assaulting Frenchman Thomas Drouet. Authorities allege John Tomic head-butted Drouet, breaking his nose, knocking him unconscious and injuring his back.

John Tomic was said to have  burst into tears when  questioned on the stand about the incident on Monday.

Police said that Bernard Tomic told them when they arrived on the scene that his father attacked Drouet, but Bernard denied he said it during his testimony today.

"No I didn't say that. I said there was a situation and that was it, mind you the police English was very bad," Bernard Tomic said, according to a News Limited Network report. "I was checking in (to the hotel) and all of a sudden my dad came in with blood on his face saying 'He hit me'."

John Tomic then alleged that it was Drouet who punched him.

"He grabbed me and he pulled me around to him, and he tried to hit me and then he fell, I don't know how he fell," John Tomic said. “There were some people there and I said 'He hit me.' He fell down I don't know how. Then I went into the hotel reception and I saw Bernard and I say to him 'He hit me and fell down I don't know how.' "

John Tomic also denied that he admitted to police that he hit Drouet and broke down in tears on the stand.

"I never said I hit him... they had a translator on the phone... they all spoke bad English, I didn't hit him and I didn't say I hit him," John Tomic said.

The police officer who arrived on the scene said he understood both Tomics and said John Tomic admitted attacking Drouet.

"I went to talk to [John] Tomic and he told me himself: He attacked him; with my English level I understood perfectly what he was telling me. He was telling me 'I hit him' and he mimicked actions," said the officer.