LONDON, May 7 (Xinhua) -- The father of Australian tennis player Bernard Tomic was banned while ATP investigated into an alleged assault of Tomic's training partner.

John Tomic was charged with assault after allegedly head-butting the hitting partner, Thomas Drouet, on Saturday outside the player hotel ahead this week's Madrid Open.

The men's professional tennis governing body said Tuesday that following the "ensuring investigation", John Tomic will have his credential privileges "suspended at all ATP tournaments until further notice".

ATP also said in the statement that investigation into this incident remains on-going.