Sanzaar CEO Andy Marinos has reportedly denied claims that South Africa are set to shun the Rugby Championship this year and play in the north instead.
The world champion Springboks, who were also the 2019 Rugby Championship winners, are likely to join the new eight-team northern hemisphere tournament at the end of this year, according to French media.
Japan have pulled out because of Covid-19 travel restrictions, and World Rugby vice-chairman Bernard Laporte told Le Progress in France there are "advanced discussions" with South Africa.
"The Japanese will not come to Europe....we are looking for a nation to replace them. We are in advanced talks with South Africa. It would be great to be able to face the Springboks, world champions in the title, but it's not yet done," Laporte said.
Marinos has told Newshub there is "no substance" to the story.
Last week Marinos said New Zealand was still set to host the Rugby Championship in November and December, with West Australia a back-up option.