Most days, conversation under the sunshades by the clay courts of Dax Tennis Club revolves around lighthearted gossip rather than match tactics. It is a club with a recreational emphasis, where a player such as Maxime Fauviau, 16, feels at home.

In top form, Maxime is what you would call a good player at regional level. He has a strong tactical sense, plays about two tournaments a month in southeastern France, and wins about half his matches.

His 13-year-old sister, Valentine, on the other hand, is in another league. Already sponsored by adidas, and recently back from two tournaments in Egypt, she has that extra magic that makes the difference between Grand Slam dreams and Maxime's tennis-playing reality.


Even though Valentine's backhand still has the awkwardness of a child with a racket too big for her, she has reason to see herself playing in the French Open at Roland Garros one day. For Maxime, a good day might see him winning a Bayonne smoked ham or a shopping voucher.

To judge by the snap psychological analysis beneath the sunshades this week, the difference between sister and brother became too much to bear for their father. Last Sunday, 43-year-old Christophe Fauviau was arrested and placed under formal investigation on charges that, during matches, he spiked the drinks of Maxime's opponents with an antidepressant drug, Temesta (lorazepam).

When one of the opponents, Alexandre Lagadere, 25, died last month after falling asleep at the wheel of his car, the antics of an overkeen tennis dad shifted from the realm of the quaintly mad to the deadly.

"His behaviour was illogical," said Jacques Dupre, the chairman of the Cote Basque Bearn Tennis League and secretary general of the French Tennis Federation.

Gendarmes investigating the death of Lagadere and other suspected cases of poisoning by Fauviau believe he only intervened to subdue his son's opponents, never those of Valentine.

"There was no financial or sporting incentive to do this, because Maxime was not playing tournaments for ranking, nor for real prize money," said Dupre. "He is a good player at regional level, but he is already 16 and not champion material."

But Dupre admitted Fauviau had all the hallmarks of a pushy tennis dad - every bit as domineering as the Mary Pierce, Jelena Dokic or Steffi Graf parents who live vicariously through their daughters' triumphs, as does Richard Williams, father of the all-conquering Venus and Serena.

It was the behaviour of Jim Pierce, the father of Canadian-born Frenchwoman Mary, that prompted the creation of the "Pierce rule", banning abusive conduct by players, coaches and relatives.

In Australia, Dokic's father, Damir, is the best known of the tennis dads after his extraordinary scenes caused trouble at Wimbledon and where Dokic's short-term stint as an Australian ended in tears.

In the case of Peter Graf, father and coach of Steffi, it was a 45-month jail sentence for non-payment of taxes that got him out of the stands.

In Fauviau's case, said Dupre, the tennis federation has intervened several times during Valentine's young career.

"At one point we were advising him to send Valentine to our tennis academy at Toulouse. He refused, so we drew up a schedule of 16 hours a week of tennis for her, as well as time for schooling, leisure and medical checks."

In spite of continued interference from Fauviau, the federation last year succeeded in getting a boarder's bursary for Valentine to attend an elite tennis academy in Paris, where she could build her ranking through a gradual round of tournaments rather than going for prestigious championships and almost certain burnout.

Players at Dax Tennis Club believe Fauviau, a retired army colonel, felt a sense of personal failure when he lost control of Valentine's career. Perhaps as a result he decided to try to expand Maxime's moderate talent into something it could never live up to without cheating.

Captain Christian Flagella of the gendarmerie said Fauviau, who was taken into custody on Monday, will be interviewed by psychologists in the course of the investigation. It already covers two suspected cases of poisoning apart from the one which led to Lagadere's accidental death on July 3.

Flagella said that hours before his death, Lagadere, a schoolteacher from Donzac in the Landes region around Dax, played a non-tournament match against Maxime.

The match started at 6pm, but Lagadere had to abandon play after one set because of fatigue. He got into his car and drove to a friend's house to rest.

He left the house at 11pm to drive home. A few minutes later, his car left the road and he was dead.

"The circumstances were surprising," said Flagella. "There were no signs of skid marks on the road and no other car involved, so we did a full range of blood tests on the body. We found Temesta, and we believe Lagadere was particularly vulnerable to its side-effects because he was completely unaccustomed to taking such a drug.

"Coincidentally, two other tennis players had approached the gendarmerie in Mont de Marsan on the eve of Lagadere's accident. One of them told my colleagues that he had seen the suspect tamper with his water bottle in the locker room before a semifinal match on June 28. He had avoided drinking from it and later taken it to the gendarmes. The other player had been hospitalised for two days after falling ill following a match against Maxime on 29 June," Flagella says.

The gendarmerie has not yet established whether the second player's illness was linked to a spiked drink. Flagella says analysis of the water bottle brought to them by the first player found traces of Temesta, which is a prescription drug.

Flagella would not say how many other suspected cases of Temesta poisoning are being linked to the ambitious tennis dad.

However, Fauviau has been placed under investigation on a double count - "administering a harmful substance which led to death, or absence from work for up to eight days". This would indicate that several of Maxime's opponents may have been targeted over a long period, and it does not rule out investigation of Valentine's opponents from the period before she was moved to the tennis academy in Paris.

Dupre says that he has never known of a case such as this in French tennis. "It is an isolated incident of irrational behaviour by a man who lost his senses." But Francoise Fraisse, a paediatrician and psychologist at the French National Sports Institute, says Fauviau's actions are in line with behaviour she has seen in ambitious parents.

"They choose individualistic sports for their children, such as figure-skating, tennis and, to a lesser degree, gymnastics." These disciplines, unlike team sports, require the parent to be present often and to stay with the child.

"I cannot say I am surprised by this case," Fraisse says. "Tennis is a potentially lucrative and glamorous sport and parents get swept up in the adventure of it. Many tell themselves their child has extraordinary talent and, as if to prove this to themselves, they take the child out of school and subscribe to correspondence lessons."

The players at Dax Tennis Club would like the chat under the sunshades to return to gentle gossip. Alexandre Lagadere, the schoolteacher who died - all the evidence suggests - after his car left the road due to a few too many innocent slurps from an "energy drink", also had an ambition - to umpire at the French Open.

Now, the only person who can still make it on to the centre court at Roland Garros - by fair means or foul - is Valentine.