World Rugby's Executive Committee had decided that replaying the fixture "would be in the best interests of the game" following a row over an official.

Eligibility issues have also since emerged which could also lead to sanctions for the countries involved.

An independent Disputes Committee has been convened by World Rugby to examine the various issues.

The world governing body had previously pledged to investigate after Romania controversially qualified for the World Cup in Japan at the expense of Spain.

Spain lost their final 2018 Rugby Europe Championship match 18-10 to Belgium in Brussels which saw their rivals qualify instead, but they were left angered by decisions made by Romanian referee Vlad Iordăchescu.

Players were seen angrily remonstrating with Iordăchescu and he had to be escorted from the field. 

Spain could still qualify for Japan 2019 but would have to enter a play-off system involving Portugal and Samoa and the Pacific Islanders would be highly fancied.

A formal complaint has been lodged by the Spanish Rugby Federation, who demanded a replay.

They also requested a change of officials before the game but this reportedly could not happen as Rugby Europe appointed them months in advance and before any permutations were known. 

Rugby Europe's President is Romanian International Olympic Committee member Octavian Morariu, to add further intrigue to the crisis.

It now seems the eligibility issues will have to be resolved by the World Rugby Disputes Committee before a replay can be officially ordered.

"World Rugby was deeply concerned about the circumstances surrounding the Belgium versus Spain Rugby Europe Championship match, a match that was decisive in the context of Rugby World Cup 2019 qualification," a World Rugby statement said today.

"Specifically, concerns related to the process and perception of Rugby Europe's appointment of a match official team that was not neutral in the context of qualification and failing to act on Spain's concerns in respect of the appointment.

"While recognising Rugby Europe's responsibility to review events in their own competition, given the context and significance of the fixture World Rugby acted immediately to request information relating to the above issues from Rugby Europe and participating unions.

"Having considered all available information, the World Rugby Executive Committee and Rugby World Cup Board felt that a replay would be in the best interests of the game.

"Since expressing that view, new information relating to player eligibility in the Rugby Europe Championship has been presented to World Rugby by the participating unions.

"Given this information concerns potential breaches of World Rugby regulations, and given the complexity and inter-connectivity of the issues, a full and independent review is warranted. 

"This is in the best interests of the sport, teams and fans and is fully supported by Rugby Europe."

Romania have provisionally been placed with Six Nations champions Ireland, Scotland, hosts Japan and a play-off winner in Pool A.

Reward also comes in the form of playing the home side in the opening match in Tokyo on September 20 next year.

A separate independent judicial panel has been appointed by Rugby Europe to consider the conduct of players after the Spain versus Belgium fixture.