Prosecutors at Spain's top criminal court said Monday they had opened a preliminary investigation into Spanish football chief Luis Rubiales, who forcibly kissed player Jennifer Hermoso on the lips after Spain's victory at the Women's World Cup.

"Prosecutors from the National Court have opened a preliminary investigation to look into the facts, which could constitute an offense of sexual assault," a court statement said.

They would also contact Hermoso to offer her a chance to file a suit within 15 days, the statement said.

After Spain won the Women's World Cup in Sydney on August 20, Rubiales sparked a massive backlash after forcibly kissing midfielder Hermoso on the lips during the medal ceremony. 

Hermoso later said the unwanted kiss had left her feeling "vulnerable" and like the "victim of an assault," with a statement on social media describing it as "an impulse-driven, sexist, out of place act without any consent on my part."

At a meeting of the Royal Spanish Football Federation (RFEF), Rubiales said he was a victim of "social assassination" and insisted the kiss with Hermoso was "mutual" and "with consent," and that he "would not resign."

Hermoso denied Rubiales' claim, as members of the Spanish women's national team signed a joint statement saying they would not play for their country again while Rubiales remains president of the RFEF.

At the weekend, the world football governing body FIFA suspended Rubiales as president of Spain's RFEF football federation for three months. 

He could face further sanctions in Spain, with the country's National Sports Council (CSD) meeting on Monday to discuss and examine the complaints against him. 

According to Spanish media, Rubiales' mother has gone on a hunger strike because of what she described to the Spanish media as an "inhuman hunt" against her son.

(With input from AFP)