France on Thursday indefinitely suspended star striker Karim Benzema over criminal charges of involvement in a sex-tape blackmail attempt against teammate Mathieu Valbuena.

French Football Federation (FFF) president Noel Le Graet said the suspension would include the 2016 European Championship, which starts in France in exactly six months, unless the case is settled beforehand.

Real Madrid star Benzema took the outcome in stride, tweeting that he respected the decision.

"I respect the decision and have confidence in our president Noel Le Graet @FFF @equipedefrance," he tweeted.

Le Graet said it was a "heartbreaking" decision to take the action against the 27-year-old, who is the top scorer among all current France internationals.

"Karim Benzema will not be selected until the situation changes, until there is something new in the case. It is a decision I took as president of the federation," Le Graet told a media conference.

However, Real issued a statement in which it said it was standing by the player.

"Real Madrid regrets but respects the decision taken by the French Football Federation to provisionally suspend Karim Benzema from the France national team, and wishes to reiterate once more its support for and confidence in the player," said the club.

Benzema has been charged with complicity in the attempt to blackmail 31-year-old Lyon midfielder Valbuena.

He has denied any wrongdoing but could face a five-year jail term if found guilty.

Valbuena has said the sex images were on a mobile telephone that was stolen.

Three men have been detained for the cash demand to have the tape destroyed.

Le Graet said that either the charges had to be dropped or Benzema, who has scored 27 goals in 81 internationals, and Valbuena had to reconcile.

"If there is no change in March (when the next internationals are held) he will not play. If there is no change for the Euro he will not play," Le Graet declared.

Valbuena was left out of France's most recent squad because of the affair, but he is now free to play again, the president added.

Le Graet's announcement came just two days before the draw for the Euro 2016 finals is held in Paris.

Le Graet said that the Real Madrid star was an "extraordinary" player but that the FFF had to take account of public opinion after facing strong pressure over the case.

French soccer's embarrassment had been increased because Benzema is alleged to have approached Valbuena at a national training camp on Oct 5 to encourage him to speak to the blackmailers, one of whom was a close childhood friend.

Valbuena has said that Benzema "indirectly" urged him to pay.

Last month a French radio station gave details of a telephone conversation that Benzema had with Karim Zenati, a childhood friend and one of the three alleged ringleaders.

Benzema said he told Valbuena he had to go to see the blackmailer but was also quoted as saying "I give you my word that there is no other copy" of the sex-tape.

Benzema has said he was just trying to help a friend in trouble. He has also said he was the target of "persecution" over the case.

The scandal has brought chaos to France's preparations for the Euros, with even Prime Minister Manuel Valls calling for Benzema to be excluded from the national team.

French Football League (LFP) president Frederic Thiriez also said that "wearing the blue shirt is not something ordinary.

"An exemplary attitude must come before even performance, if we want to win over hearts."

"The French team is regularly shaken by scandals which feed a growing disillusionment among our compatriots," Thiriez said.

Benzema has said he has the support of coach Didier Deschamps, and others have given him backing - including French legend Zinedine Zidane, who said the player should not be suspended.

"A player like Benzema is an important player for the team, he can bring so much to the team," Zidane said.

"In sporting terms, to cope without a player like that can be complicated, because it affects the whole team."