Philippoussis, father of retired Australian tennis star Mark, was arrested at his home in San Diego on Tuesday. 

The 68-year-old was arrested on suspicion of sexually abusing two nine-year-old girls that he had been privately coaching. 

It was alleged Philippoussis abused the girls in different San Diego locations, including his home, his car and a tennis complex. 

If convicted, he faces a maximum jail sentence of 21 years to life.

However, his lawyer Ryan Tegnelia said his client was innocent and would fight the charges.