Lazio have backed suspended Jaap Stam tonight following his positive test for the banned steroid Nandrolone. Club president Sergio Cragnotti said that he was "astonished" at the news, while the club's doctor insisted he and his team have taken all possible steps to ensure players use only permitted supplements.

Former Manchester United star Stam is the second player at the Serie A club to test positive for the banned substance. Portuguese international Fernando Couto has just returned from a ban. Fellow Dutchmen Edgar Davids of Juventus, and Frank De Boer of Barcelona have returned to action following suspensions for positive nandrolone tests.

Stam was suspended with immediate effect by the Italian Olympic Committee today. He was tested following the 13 October match between Lazio and Atalanta. He has been found positive in the first analysis and will be immediately suspended from all sporting activities. New Italian drug-testing rules, which came into effect on 21 October, state a player can be suspended after a first test. Previously, players would have had to fail two tests before a suspension could be handed down.

Stam was sold by Manchester United for £16.5m in August. The Dutch international left Old Trafford in controversial circumstances after his autobiography was serialised in a British tabloid newspaper. He had claimed in the book that Alex Ferguson had approached him without the approval of PSV Eindhoven officials before his move to Old Trafford. He also criticised team mates but Ferguson insisted that Stam was sold for footballing reasons.

Filed by Greg McKevitt