A revolutionary 12-a-side competition planned for next year appears to have been killed off by World Rugby.

After consultation with stakeholders, World Rugby "do not wish to explore the concept further at this time".

A World Rugby spokesperson said the sport's priority was "advancing discussions" on a "harmonious annual international calendar".

The spokesperson said: "This is a position endorsed by the World Rugby executive committee and professional game committee, which includes representatives from across the elite men's and women's game."

However, sources at World 12s have told the BBC they are not yet "raising the white flag" and say the issue is more around the timing of the fledgling tournament than the concept itself.

The tournament's newly-appointed chief executive Rowena Samarasinhe said: "World 12s has been, and continues to be, in regular contact with World Rugby.

"The challenges around the international calendar are well known. World 12s is a long-term project and will grow over the years.

"We are optimistic that, even within the restrictions posed by the current calendar, World 12s will be able to host a tournament in August 2022 that includes a number of the game's leading players, who will not be impacted by fixture clashes at that time."

Backed by luminaries such as World Cup-winning coaches Steve Hansen and Jake White, the World 12s hoped to launch next August in rugby's equivalent of the Indian Premier League.

But the announcement blindsided the game's authorities, while it is also understood CVC - the capital equity giant which has a commercial foothold in the Premiership, the United Rugby Championship and the Six Nations - were also not consulted and do not support the venture.

The tournament - due to be held in England - was intended to take place across three weekends and feature 192 of the world's best players, picked via auction to represent eight franchises.