The future of PRO Rugby is shrouded in uncertainty after the players were informed their contracts were being terminated by the league's owner Doug Schoninger.

A post on the PRO Rugby Facebook page read: "Unfortunately, due to issues beyond our control, we were forced to activate the voluntary termination clause in our player's agreements. We are hoping for a productive resolution as soon as possible."

PRO Rugby is adamant the league will continue in some form in 2017 but in the letter to the players, according to Rugby Today, Schoninger says the league is having "serious issues with the cooperation and the enforcement of our agreement with USA Rugby". Schoninger hopes those issues can be resolved prior to the end of the termination clause period.

USA Rugby has since its own statement in response to Schoninger, saying: "USA Rugby categorically denies any and all allegations purported by PRO Rugby Tuesday, Dec. 20, and is saddened to hear of the planned termination of all valid contracts signed by athletes that have fulfilled their playing duties for season one and were scheduled to be paid through the duration of their 12-month contracts."

The first season of the five-team competition finished in July with Denver Stampede winning the title but since then one of those quintet -- the San Francisco Rush -- has folded.