Mark Philippoussis
Mark Philippoussis of Australia celebrates during his World Tennis Challenge match against Goran Ivanisevic of Croatia at Memorial Drive in Adelaide, Australia, Jan. 12, 2017. Getty Images

The 40-year-old retired Australian tennis ace Mark Philippoussis faced quite a few embarrassing moments this week after his father Nikolaos Philippoussis, 68, was arrested Tuesday on the suspicion of molesting two girls. He was slapped with an increased bail of $9.2 million fine Thursday from the previous $2.5 million which was announced Wednesday.

Nikolaos, who had also pleaded not guilty to 14 counts of sexually assaulting his two students, each nine-year old, faces 210 years of life in prison if found guilty, reports said.

Nikolaos appeared at the San Diego Superior Court on Thursday and looked frail as he sat in handcuffs, leg irons, and a blue prison jumpsuit in an enclosed area. The massively increased bail on Nikolaos on Thursday did not draw opposition from his lawyers who said it was "commensurate with such grave charges." They also said that the amount could not be raised by Nikolaos anyway, a report said.

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Mark, who was a two-time Grand Slam finalist and ranked as high as eighth in the world, too lives in San Diego. He was present in the court to support his father, however, he did not comment on it.

Nikolaos worked as a private tennis instructor in San Diego County during the alleged assaults incidents. He is charged with two counts of sexual penetration/oral copulation with a student under the age of 10 and other dozen counts of obscene acts with a student under 14. The alleged crimes occurred over the last year at the Fairbanks Ranch Country Club, in a car, and at the coach's residence, the Telegraph reported citing a criminal complaint.

"Philippoussis works as a personal tennis coach in Northern San Diego County and the alleged molestation victims took tennis lessons from him. The investigation is ongoing at this time," according to the press release by San Diego County Sheriff's Department.

Deputy district attorney Garret Wong said: "I think what's most concerning is the defendant being in a position of trust, and it's probably any parent's worst nightmare of having someone in that position of trust - a teacher, a coach, an instructor - and then to violate that trust repeatedly over this amount of time, yeah, it's serious," reports said.

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Nikolaos' attorney Ryan Tegnelia said the arrest "took the entire family by surprise" adding that, "Mark's doing very well. He's of course very concerned for his father, wants to help in any way that he can. He understands the serious nature of the charges," News Mail reported.

Mark has always considered his father as his inspiration. Nikolaos coached Mark who rose to fame in the 1990s and early 2000s. In April 1999, Mark reached No. 8 in the world, which was his highest pro ranking. Mark made the finals of the 1998 U.S. Open and Wimbledon in 2003. Nikolaos was his coach until 2006 amid controversies that the two reportedly had a fallout. However, Mark had denied those rumors, according to reports.