The disclosure that an Irish international rugby player tested positive for a banned substance last season is certain to fuel suspicions about the use of performance-enhancing drugs in the sport.

The revelation that the IRFU yesterday formally received notification from the UK Sports Council, which conducts all drug-testing in rugby in the four home countries, follows a report that two home union players tested positive for banned substances last season.

Leading figures in Irish rugby had expressed indignation at claims by former Irish lock Neil Francis that Irish players have taken performance enhancing drugs over the last 10 years. Francis's claims, made in the Sunday Tribune, aroused outrage from IRFU president Noel Murphy and current Irish team manager Donal Lenihan.

Murphy called on Francis to substantiate his allegations while players such as last season's Irish captain Keith Wood, Mick Galwey and a former team-mate of Francis, Dennis McBride, all emphatically stated they had never witnessed any evidence of drug abuse.

It is still unclear as to when the aforementioned tests were carried out - although sources close to the Union believe that they took place last season. Similarly, it is not certain what kind of drug, if any, the player or players took, and most importantly whether it was performance-enhancing or purely for a medical condition.

Quite why the UK Sports Council waited until yesterday to notify the Union of its findings is decidedly curious, especially as it follows a report in the London Times that two unnamed international players from the four home unions were found positive last season for anabolic steroids.

Calls from this office to both the UK Sports Council and the IRFU yesterday afternoon elicited no such information. A spokesperson for the UK Sports Council's drug-testing section merely stated they had no knowledge of information in the Times article, before adding: "You need to go to the relevant governing body (the IRFU)."

Then the notification from the UK Sports Council arrived at Lansdowne Road late yesterday afternoon. Beyond that, neither the IRFU president Noel Murphy or the IRFU press officer John Redmond were prepared to make any further comment, Murphy explaining that "certain procedures have to be followed now".

The revelation also follows an assertion from a Scottish Rugby Union spokesman said there had been no indication of any positive results at Murrayfield.

"The SRU doesn't actually conduct the tests, the UK Sports Council does. But if there had been any positives, as a matter of course they would have been in touch with the Union," said the SRU's Derek Douglas.

The Welsh Rugby Union said it wanted to "re-affirm" that no member of its national squad was involved.

"We are pro-active in this field, and continually stress to our players the importance of avoiding any substances that may be deemed questionable," stated the WRU's director of rugby Terry Cobner.

"We co-operate with all the relevant drug testing bodies, and will wholeheartedly support any moves to increase the strictness and frequency of testing."