An initial investigation by the RFEF's competition committee has decided there is evidence to suggest that Guardiola brought the game into disrepute, and have rejected a defence case presented by the club on Monday.
Inquiry leader Rafael Alonso Martinez has one month to decide if an offence has been committed and if so what the punishment should be.
Guardiola, who led Barcelona to a six-trophy haul in 2009, was sent off in the 2-2 draw at Almeria on March 6 and an appeal against his one-match ban was rejected.
A few days later, Guardiola said: "I have seen the footage and I am not very proud. Seeing it I can understand the sending off and I don't like seeing myself like that.
"But when someone lies you have to appeal. They (the officials) lied in the match report and put things in there that I did not say."
Referee Carlos Clos Gomez wrote in his match report that he had sent Guardiola to the stands in the 27th minute for leaving his technical area and putting his face close to that of the assistant referee and shouting and waving his arms.
He quoted Guardiola as saying: "Your decisions are the wrong way around" and "You don't understand anything."
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