The World Anti-Doping Agency have welcomed the eight-year ban imposed on Mariano Puerta for a second drugs offence as "a big step forward" in the bid to clean up tennis.

The playing career of 27-year-old Argentinian Puerta is all but over after he failed a test for the banned stimulant etilefrine immediately after the French Open final, which he lost in four sets to Rafael Nadal.

The Grand Slam showpiece at Roland Garros marked an incredible revival for Puerta, who served a nine-month ban after testing positive for clenbuterol during a tournament in Vina del Mar, Chile, in February 2003.

His ranking slipped to 440 in the world and he was reduced to competing in Challenger events before returning to the ATP Tour in 2005.

He won at Casablanca before his surprise run to the French Open final in Paris.

The ban has been back-dated by the International Tennis Federation to June 5, 2005, meaning the player will be three months short of his 35th birthday when it ends. He has three weeks from receipt of the written decision to decide whether or not to appeal.

Dick Pound, the chairman of Wada, was pleased with the length of Puerta's suspension, which is in accordance with the agency's guidelines.

"Somebody who has tested positive twice in less than two years is someone who clearly doesn't think the rules apply to him," Pound said.

"We were always worried about the secrecy and apparent laxity of the testing programmes when the responsibility was in the hands of the players' association. I know that the International Tennis Federation have been working for a number of years in the interests of the sport and the process is now more transparent.

"The testing regimes will get better over time and the deterrent effect of these kind of sanctions where positive cases are discovered will I hope persuade players who might otherwise consider using these drugs not to do so."

Puerta has had his results in the French Open declared null and void and has forfeited entry ranking points and prize money of 443,282 euros (£300,671).

From January 1, the ITF will manage, administrate and enforce the sport's anti-doping programme at ATPsanctioned events. n Uefa have rejected Middlesbrough defender Abel Xavier's appeal against the 18-month ban imposed for testing positive for an anabolic steroid.

The 33-year-old became the first Premiership player to be found to have taken performance-enhancing drugs when a routine test showed the presence of methandienone, also known as dianabol, a steroid mainly used by body-builders.

The test took place following Boro's Uefa Cup match against Greek side Xanthi on September 29 and he was given the suspension at a personal hearing at Uefa headquarters in Nyon last month.

A statement from European football's governing body stated: "Middlesbrough FC defender Abel Xavier has failed in his appeal against an 18-month suspension for a breach of anti-doping regulations.

"Uefa's appeals body met today to consider Xavier's case after he appealed against a November 23 ruling by Uefa's control and disciplinary committee."

Xavier can appeal to the Court of Arbitration for Sport within ten days of being notified in writing of the decision.

Boro signed the former Portugal international on a free transfer in August after his release by Roma. He also had spells at Everton and Liverpool. ..SUPL: