Cracks in her relationship with the organisation began after it opposed the double Olympic gold medal-winning medallist's decision to enlist her husband Anthony Lobello as coach after Pyeongchang 2018.

"I decided to stick to the trip Anthony was already planning here to see what the US and SLC (Salt Lake City) have to offer if I were to continue my Olympic trip," short track speed skater Fontana wrote on Instagram.

"I'd like to thank the coaches and training groups I skated with while I was here.

"Thank you for welcoming me and my coach with open arms."

The 32-year-old Fontana claimed that there has been no constructive talks from the FISG about her participation at Milan Cortina 2026 since last April.

The situation escalated when Fontana claimed she had harassed by male national team athletes and the issue was not addressed by staff.

"As long as those decisions and actions are approved, I will not come back and if I decide to compete in the future, my path will be completely separate from what the technical director and his staff have planned for the Italian group," Fontana said.

"In that case, I will be sorry not to train with the rest of the Italian athletes, but my trust in the technical and federal staff is unrecoverable.

"I have important decisions in front of me to make and all the cards are on the table, even the ones I thought I would never consider."

Fontana's former coach Stelio Conti has weighed into the situation and warned that the possibility of her competing for the US is "quite real".

FISG responded with a statement in which it expressed "its astonishment and regret for the serious remarks" made by Fontana, calling them unhelpful amid efforts to prepare for the Milan Cortina 2026.

"Medals are and remain important, but they will never be more important than respect, education, professionalism and fair play," the organisation said.

At Beijing 2022, Fontana won three medals, including 500 metres gold, retaining the title she had won at Pyeongchang 2018 to bring her personal Olympic medal haul to 11.

Beijing 2022 was the fifth consecutive Games she had won an Olympic medal.

Fontana won a bronze at Turin 2006, the last time Italy hosted the Winter Olympics, and Vancouver 2010.

That was followed by a silver and two bronze at Sochi 2014, a gold, silver and bronze at Pyeongchang 2018 and gold and two silver at Beijing 2022. 

That has left Fontana just two shy of fencer Edoardo Mangiarotti's Italia record of 13 won from Berlin 1936 to Rome 1960.

Fontana had previously stated that if she does compete at Milan Cortina 2026 it will be her last appearance at the Games.