An agency inquiry found that Queiroz insulted an anti-doping team sent to test the Portugal squad ahead of the World Cup and that his aggressive behavior disrupted their work, national news agency Lusa and other media said.
Officials at the agency were not available for comment on the reports. The Portuguese Football Federation said in a statement on its website that the agency has not informed it of any ruling and that it will not comment until it receives notification.
Queiroz said in a statement that neither he nor his lawyer had been informed of any official decision. However, he said if it is true he will appeal against the ruling to the Court of Arbitration for Sport in Switzerland.
He said in the statement sent to national media that convicting him of interfering in a doping test would be "totally wrong, harsh and unfounded." The federation earlier this month suspended Queiroz for one month on a charge of misconduct related to the same incident at Portugal's pre-World Cup training camp in May.
Officials sent to carry out routine tests on Portugal players said Queiroz harassed and intimidated them and used foul language, according to media reports. Details of the inquiry have not been made public.
Queiroz has said he was angry that the unannounced early morning tests had disturbed the players and admitted that he used inappropriate language but denied disrupting the tests. None of the players tested positive.
Queiroz, who has spent two years as Portugal coach, has fought the charges. Earlier this month, Manchester United coach Alex Ferguson testified on Queiroz's behalf as a character witness. Queiroz was previously Ferguson's assistant at Old Trafford.
Portugal produced a disappointing World Cup campaign in South Africa, where it went out in the second round against eventual champion Spain.
Portugal's first qualifying games for the 2012 European Championship are against Cyprus on Friday and Norway four days later, when Queiroz's assistant Agostinho Oliveira will be in charge. Group H also includes Denmark and Iceland.
If confirmed, the agency's ruling will increase pressure on the federation to find a replacement for Queiroz, who would have to sit out four of Portugal's Euro 2012 qualifying games.
It would also deliver another blow to Portuguese hopes of making a strong start to its campaign after captain Cristiano Ronaldo was ruled out of the first two matches after picking up an injury last weekend playing for Real Madrid.
Also, midfielder Deco, winger Simao Sabrosa and defender Paulo Ferreira — three of Portugal's most capped players — have all retired from international football since the World Cup.
