Justine Henin-Hardenne vigorously denied insinuations that she was doped when she beat Belgian rival Kim Clijsters at the U.S. Open last week.

Henin-Hardenne told reporters upon her arrival at Brussels airport from the United States that the only secret of her success is hard work.

"I have never been tempted by doping," she was quoted as telling reporters in the daily Le Soir on Wednesday. "My only doping is work. I am ready to undergo whatever test, wherever, whenever to prove that my body is clean.

"I do not take any product, whatever they might be, apart from the water and other energy drinks prepared by the WTA," she added.

Henin-Hardenne has now won two Grand Slams, both at the expense of world number one Clijsters in the final.

On her return to Belgium, she was received by fans as well as reporters anxious to get her reaction to comments made by Clijsters's father Leo about her apparent weight and muscle gain.

PHYSICAL TRANSFORMATION

Leo and other pundits were quoted in the local media as saying her physical transformation was unusual. None of them mentioned doping.

The growing tensions between the two players -- who have previously declared themselves as friends -- and their entourage also highlight the linguistic and cultural divide in this small European country of 10 million people.

Henin-Hardenne is from the francophone south, while Clijsters is from the Dutch-speaking north.

Henin-Hardenne's coach, Carlos Rodriguez, was quoted in the local press as accusing Leo Clijsters of spreading rumours out of jealousy.

"In Belgium, what we are trying to do is to start a fight between these two girls," he said.

"I swear on the heads of my two sons that she has never taken doping products," he said. "In Belgium, we want absolutely to create a fight between the two girls.

"Justine is better than Kim and will win more often than her," he said. "In six months, Justine has become a different player, a lot stronger. I know that she works very hard but she is not the only one. All players, including Kim, work on their muscular force."

Her victory over Clijsters last weekend was remarkable.

Henin-Hardenne had returned to the court after spending hours in an infirmary bed with an intravenous drip in her arm.

She had been suffering from exhaustion, cramps and dehydration following a three-set semi-final win over Jennifer Capriati.