Dougie Walker has struck another blow against the International Amateur Athletic Federation's (IAAF) policy on nandrolone positives just a day after it had to reinstate the Jamaican sprinter Merlene Ottey.

Lawyers for Britain's European 200 metres champion, who tested positive for the banned anabolic steroid in December 1998, yesterday blocked an application in the high court in London by the world governing body for his case against it to be struck out.

Walker is suing the IAAF because he claims that, having already been cleared by his national governing body, UK Athletics, it does not have the authority to try him again in the same case. The high court backed Walker and ordered a speedy trial, which could force the cancellation of the Scot's IAAF arbitration hearing, currently scheduled for August.

His lawyer, Nick Bitel, believes Ottey could be a landmark decision. The arbitration panel explained in a statement late on Monday "that there were not the grounds to maintain the suspension" and ordered she be reinstated immediately.

"Both cases are not directly referrable - the science in Ottey's case was important and the circumstances surrounding the two are slightly different," said Bitel.

"However, the whole Ottey case questions the levels of nandrolone in the body. But the IAAF jump in with their jackboots and ban everybody. It is encouraging they failed in a such a high-profile case."

The 1992 Olympic 100 metres champion Linford Christie, 400 metres runner Mark Richardson and hurdler Gary Cadogan are also seeking to have lifted suspensions for nandrolone positives.

Ottey, winner of 34 medals in major championships, including a record 14 in world championships, was banned after testing positive last July. She is now determined to compete in her final Olympics, in Sydney, at the age of 40.

"It has been a difficult and emotionally draining time for me," said Ottey. "However, I have been training well and I am looking forward to my first competition."

She plans to make her comeback soon in a low-key meeting before heading to Jamaica for the Olympic trials at the end of the month.

Marie-Jose Perec, one of Ottey's oldest rivals, launches her own comeback in the Athletis sima meeting in Lausanne today when she begins the build-up to her attempt on an unprecedented third consecutive Olympic 400 metres title.