While the seedy underbelly of men’s tennis has been exposed and examined amid rumours of match-fixing and corruption, the women’s game had escaped relatively unscathed until the revelations last week that Martina Hingis had tested positive for cocaine during Wimbledon this year. Justine Henin, the world No 1, used the platform of the WTA’s showpiece event, the year-ending Sony Ericsson Championships in Madrid, to again underline the necessity to cleanse the game of such unwelcome intrusions.

“My tolerance in doping and match-fixing is zero, but we can’t accuse anyone until we have proof,” the Belgian said yesterday. “It is unfortunately a scourge that appears to affect all sports, but we have to make sure it doesn’t affect tennis. On match-fixing, the only thing I can say is that I’ve never been approached by anyone about anything and I’ve never heard about anything like it.

“For doping, it is the same. I don’t want to make any comment about Martina’s situation, but we want to keep a clean sport and a healthy sport because we all give our best when we play. We want to make sure people keep loving tennis.”

That has been hard to do at times for Henin, who has endured an emotional rollercoaster of a year. After missing the Australian Open because of the break-up of her four-year marriage to Pierre-Yves Hardenne, the diminutive Belgian, whose mother died when she was 12, questioned whether she had the emotional capacity to return to the game’s summit. In April, a reconciliation with her family, with whom she had been embroiled in a bitter feud for eight years, over the hospital bed of her brother, David, who was recovering after a car crash had left him in a coma, signalled the beginning of the healing process. The 25-year-old went on to win the French Open for the fourth time, reached the semi-finals of Wimbledon and enjoyed a second victory at the US Open in September.

During the presentation ceremony at Flushing Meadows she was introduced to the crowd as Justine Henin-Hardenne – the marital name a wince-inducing reminder of how far down the road to recovery she had travelled. (It was an improvement on 2004, at least, when she was referred to by a sponsor as Christine).

Henin has the opportunity to complete that journey when she begins the defence of her crown in Madrid today – she plays Anna Chakvetadze, the Russian, who is making her debut in the event – and the tournament favourite took the time to ruminate over a remarkable year.

“I always believe that impossible is nothing and I proved that again this year because when I look back to the way I felt in January and when I came back to competition again [in Paris in February], it was like I had to start my career all over again,” she said.

“I had to deal with a lot of emotions. So it’s been a difficult year, a very difficult year, but it’s been a great school of life.” Henin has also had to contend with physical woes. She suffers from asthma – a condition that, she revealed yesterday, could affect her ability to compete in the polluted air of Beijing at the Olympic Games next year – and a weak immune system that means she must follow a regimented diet.

But this is the first year in which she will have been able to complete a full season and she sounded an ominous message to her opponents in Madrid this week.

“Physically I have felt much better this year,” she said. “It is the first season I have completed, so it was a goal for me to remain healthy. I come here in good shape and it’s a gift for me to be here. It’s been a fantastic season; we all fought a lot to be here and I’m excited to start tomorrow.”

It must be hoped that the organisers, who put on such a successful tournament last year, can get her name right.

How it works

Yellow group: Justine Henin, Jelena Jankovic, Serena Williams, Anna Chakvetadze

Red group: Svetlana Kuznetsova, Ana Ivanovic, Maria Sharapova, Daniela Hantuchova

The top eight players in the Sony Ericsson WTA Tour Race compete for the winner’s cheque of $1 million (about £500,000). The tournament begins in round-robin format, with each player facing everyone in their group. In the semi-finals on Saturday, the best player from the Red group plays the second-best player in the Yellow group and vice versa. The final takes place on Sunday.