RIO DE JANEIRO - Former Portugal star Deco is free to resume his career after a Brazilian sports tribunal accepted Friday that he unwittingly took a banned substance.

But a doping panel ruled the 35-year-old was responsible for his actions and handed him a 30-day suspension. The penalty was backdated to May 7, meaning he can play immediately for his club Fluminense.

Deco expressed a mixture of frustration and relief upon leaving the hearing on Friday night, claiming the episode had stained his reputation.

"In my opinion it is unfair. I should have been absolved," Deco said. "I wanted my name to be cleared because I know I am innocent. But the most important thing is that now I can get back to playing."

There had been fears Deco would be barred from playing for two years under Brazilian football's strict drug code.

Deco tested positive to the diuretic furosemide after Fluminense's Campeonato Carioca match against Boavista in April. The substance is banned due to its use as a masking agent for other drugs.

During a four-hour hearing on Friday, Deco's doctor Sergio Puppin and biochemist Luciana Figueiredo presented arguments in the midfielder's defence.

Puppin said he had prescribed vitamin supplements to help Deco overcome recurring leg muscle injuries during the past two seasons. He said the pharmacy responsible had unknowingly supplied supplements with traces of furosemide.

Figueiredo argued Deco needed a level of the substance 1000 times higher than that found in his system to feel a doping effect.

During his own testimony, Deco asked the panel to consider his controversy-free 18-year professional career, which has also included spells at Porto, Barcelona and Cheslea.

The playmaker has sought to avoid the public eye since news of his failed sample emerged last month.

But in a statement released after his failed B sample, Deco vowed he would "stop at nothing" to clear his name of the allegations.

On Saturday he will travel with his teammates to Orlando, where Fluminense will train during a two-week hiatus in Brazil's Serie A while the Confederations Cup is played.

Deco said he was determined to put the ordeal behind him.

"The decision doesn't take away what I have gone through," he said. "Now I want to end my career with dignity at a club that has always supported me and been by my side.

"Unfortunately I couldn't help Fluminense win the Copa Libertadores which was my dream. That was taken away from me. But the story hasn't finished. There is still time to put things right."