CHELSEA enforced a “zero tolerance” policy against drugs yesterday when they dismissed Adrian Mutu, the Romania striker, for gross misconduct after his positive test for cocaine. José Mourinho, the manager, also revealed that he had known about the striker’s drug-taking when he arrived at the club during the summer.

Mourinho, who joined Chelsea from FC Porto, claimed that he had heard stories about Mutu and decided to challenge him about them when pre-season training got under way. The Romanian’s reaction was to laugh it off.

“When I met Adrian on the first day of pre-season, he was with two of his advisers,” Mourinho said. “I told all three of them, right back at the beginning of July, that I have information that Adrian is on cocaine. All three were laughing about it, denying it, and said that it was a lot of lies. That it was completely untrue.

“After that, we did not speak again, but over a long period my medical staff and I felt that there was strange behaviour from the player. Sometimes he was happy, sometimes unhappy. Sometimes he was late for training, sometimes he did not arrive.”

A possible move to Juventus in August broke down and the matter reached a head when Mutu was selected as a substitute for the Champions League match away to Paris Saint-Germain on September 14. Chelsea won 3-0, but Mutu was not used. “Yet the next day,” Mourinho said, “he was saying that he was injured. No one knew how this could have happened.

“Why was he doing this? Because he wanted a move or because he was on drugs? A big question mark had started and we cannot live in this club with question marks. Yes, he was a target for testing, but there were some signals over the weeks.”

Mutu, 25, was tested on October 1 and also fell out with Mourinho over the striker’s decision to play for Romania — he is the captain — against the Czech Republic in a World Cup qualifying match this month. Mourinho said he was injured, Mutu said he was not. Mutu played.

A week later, it was revealed that he had tested positive for drugs. Mutu admitted using cocaine but then said that he had taken a substance to enhance his sexual performance. Yesterday, Chelsea had had enough.

In a statement, the club said: “We want to make clear that Chelsea has a zero tolerance policy towards drugs. This applies to both performance-enhancing drugs or so-called ‘recreational’ drugs. They have no place at our club or in sport.

“In coming to our decision, we believe that the club’s special responsibility to its fans, players, employees and other stakeholders in football regarding drugs was more important than the major financial considerations to the company.”

The financial considerations were huge. Mutu cost £15.8 million when he signed from Parma 15 months ago. As a club asset, he was valued at £12 million, which Chelsea have now written off. They will at least save on his wages of £60,000 a week and are investigating whether they will be able to seek compensation from any club that Mutu should join in the future.

That might not be for some time. The Football Association has charged Mutu with doping offences and is due to hold a hearing next week. If Mutu is suspended, which is likely given his admission of guilt, he may not be able to play until late next year.

Gordon Taylor, the chief executive of the Professional Footballers’ Association, was not pleased with Chelsea’s actions. “They have target-tested the player with a view to getting rid of him as opposed to undertaking a process of rehabilitation,” Taylor said. “You would expect any employer to be interested in the moral and social welfare of its employees.”

Gheorghe Popescu, one of two advisers present when Mourinho first met Mutu, was also unhappy. “Everybody helped Adrian except his club,” Popescu said. “Chelsea’s attitude was not one of fair play.”

In a parting gesture, Mourinho wished Mutu well. “It is the beginning of a new life for him,” he said. “I hope that he will recover from his problems. But for me, it’s done, it’s finished. No, I would never sign him again. Never.”