Prosecutors at Spain's top criminal court opened a preliminary investigation on August 28 into Spanish football chief Luis Rubiales' forcible kiss on the lips of World Cup player Jenni Hermoso on grounds it could constitute a crime of "sexual assault".
The Spanish football federation (RFEF) regional presidents then asked the 46-year-old to resign because of his "unacceptable behaviour" and called for "profound and imminent" restructuring of the organisation.
The RFEF statement leaves Rubiales shorn of allies -- some of the regional presidents had been among those who applauded his speech last Friday, in which he insisted he would not resign, and his kiss was "consensual", contested by Hermoso.
Spain's National Court said they had opened a preliminary probe into Rubiales's kiss on Hermoso at the World Cup final in Sydney on August 20, "which could constitute an offence of sexual assault".
They would also contact Hermoso to offer her a chance to file a lawsuit within 15 days, the court statement said.
After Spain won the Women's World Cup Rubiales sparked a massive backlash with his unsolicited kiss during the medal ceremony.
Hermoso later said the incident left her feeling "vulnerable and like the victim of an assault", with a statement on social media describing it as "an impulsive, macho act, out of place and with no type of consent on my part".
The National Court said it was opening the investigation in light of the "unequivocal nature" of her statements, saying it was necessary "to determine their legal significance".
"Given the public statements made by Jennifer Hermoso, the sexual act she was subjected to by (Luis) Rubiales was not consensual," the court statement said.
"In order to proceed with a case for sexual assault, harassment or sexual abuse, it will be necessary for the injured party or their legal representative to file suit."
If Hermoso decides not to file a complaint, it will make it "difficult" for prosecutors to press ahead with the case, legal sources told AFP.
World football governing body FIFA provisionally suspended Rubiales for 90 days last week while they open disciplinary proceedings against him -- but the president may have resigned before that if he heeds the request from the RFEF's 19 regional presidents.