England prop Matt Stevens has been suspended from all rugby with immediate effect after failing a drugs test.
The Bath player confessed to Sky Sports News that he had failed a test taken following a Heineken Cup clash with Glasgow in December.
Stevens has been removed from the England Elite Player Squad and suspended from all rugby with immediate effect.
In an emotional interview, the 26-year-old admitted he had already started attending counselling sessions for something "that had basically ruined his life".
"I was tested for a prohibited substance but it's not performance enhancing, so you can take what you want from that," he said.
"It's a very serious substance and something I realised over a period of time that I have an issue with. It's something I think has basically ruined my life up until this point.
"When you think about how much time people have put into my career and I have thrown it away with irresponsible behaviour.
"Like any drug problem you don't know it's happening and then it mounts up and before you know it you have a problem and an illness.
"I owe it to everyone to admit that. I want to say I'm truly, truly very sorry. I want to change my life and hopefully one day get the faith back that people had in me."
Stevens was due to be part of the England squad that flew out to Portugal on Sunday for a training camp ahead of the start of the Six Nations. No replacement has yet been named.
A statement from the Rugby Football Union read: "The Rugby Football Union has been made aware by European Rugby Cup (Ltd) of the positive doping test given by Matt Stevens following the Heineken Cup match against Glasgow Warriors in December 2008.
"The procedure for potential doping offences is clearly laid out in the ERC regulations and as such the player is immediately provisionally suspended from all competition.
"Matt has been removed from the England Elite Player Squad (EPS) and will not travel to the training camp in Portugal on Sunday or be involved in the squad until the resolution of the case when a further decision on his inclusion in the England squad will be made.
"A decision on a replacement for Matt in the EPS squad is being considered by England team manager Martin Johnson and an announcement will be made in due course."
Bath also released a statement confirming that the player would be banned until the case was resolved.
"Bath Rugby has been made aware of the initial positive test given by Matt Stevens following the Heineken Cup match against Glasgow Warriors in December," the statement read.
"The procedure for potential doping offences is clearly laid out in both the player's contract and the European Rugby Cup regulations.
"The player is immediately suspended from competition and has been suspended by Bath Rugby until the case is resolved.
"Bath Rugby condemns the use of prohibited substances as defined by the World Anti-Doping Agency prohibited list."