Super Rugby bosses have branded a report that three more South African teams are set to withdraw from the competition to play in Europe as "simply wrong".
The Durban-based Sharks have been named as the first to leave the current Super set-up to join the European PRO14 competition for 2019/20, according to a report in Wales Online.
The Cheetahs and Kings, who were cut from the down-sized Super Rugby last year, already play in the competition which includes teams form Ireland, Italy, Scotland and Wales.
The report said that the Lions and Stormers would likely follow suit by at least the start of the 2020/21 season.
But SANZAAR, organisers of Super Rugby and the Rugby Championship said the report was unfounded and South Africa, Australia, New Zealand and Argentina remained committed to future participation.
"SANZAAR - through its joint venture partners - Australia, Argentina, New Zealand and South Africa - is currently engaged in a detailed strategic planning process that will deliver a road-map for the organisation, Super Rugby and The Rugby Championship from 2018-2030," SANZAAR chief executive Andy Marinos said in a statement on Monday.
"As part of this process the partners have fully committed to the strategy and future participation.
"Any talk of a change to the stakeholder relationship and partners withdrawing, and so-called trans-Tasman competitions is unsubstantiated speculation and simply wrong."
Despite the Lions making the Super Rugby final last year, South Africa's franchises are understood to feel they are handicapped due to the different time zones.
South African rugby has also seen an exodus of top players who chase lucrative deals in Europe, with the move to the PRO14 considered a way of stopping that trend.
The Cheetahs finished third in their conference this season to make the play-offs, and PRO14 organisers believe the inclusion of further South African sides would increase the standard of the competition.
Last week a Fairfax report revealed that Super Rugby bosses were looking at expanding into the USA, which now appears to be a contingency plan should the South African franchises jump ship.
Wales Online says the PRO14 income from television rights has risen from PS12million ($A22 million) to between PS20million and PS30million with a new deal for pay TV outfit Premier Sports to take over the broadcasting from next season.