Spain would have qualified directly for next year's World Cup in Japan at the expense of Romania with victory in Brussels on March 18th.
But, in a match refereed by a Romanian, Belgium won 18-10.
At the final whistle outraged Spanish players surrounded the referee, Vlad Iordachescu.
Octavian Morariu, the president of Rugby Europe, which organises qualification for countries outside the Six Nations, is also Romanian.
Spain have asked for a replay.
Spain's Fabien Perrin reacts during the rugby union match between the Black Devils. Photo: AFP
On Tuesday, a Rugby Europe judicial committee, led by Glasgow University professor Lorne Crerar, considered the cases of five Spanish players “cited for the overflow” at the end of the match.
It handed the most severe punishments to two French-born brothers who play scrum-half and were both found guilty of physical and verbal abuse of the referee.
Sebastien Rouet, who started on the bench, was banned for 43 weeks, his brother Guillaume, who started the game, received 36 weeks.
The two flankers, Pierre Barthere and Lucas Guillaume, and fly-half Mathieu Belie were found guilty of “threatening actions/words at a match official” and each banned for 14 weeks.
The punishments apply to all levels of rugby and start at once.
That means the players will be absent for Spain's play-off against first Portugal and, if they win, home and away against Samoa on June 9th and 23rd.
The committee postponed a decision on whether to punish the Spanish Rugby Union.