France legend Zinedine Zidane has been threatened with suspension from his current role as Real Madrid's reserve team coach because he has not validated his coaching badge, according to a club source.

"We've received a notification (from the Spanish Federation) detailing a possible suspension. We have 10 days to present our defence, which is what Real will do," said a spokesperson for the 10-time European champions.

Zidane holds a UEFA 'A' licence level two coaching badge but needs a level three licence to operate in the Spanish third tier, in which Real Madrid Castilla, the club's reserve side, play.

Yet since the beginning of the season the two-goal star from France's 1998 World Cup success on home soil has been nonetheless coaching the team.

He risks a three-month suspension for the offence, according to popular Spanish dailies As and Marca.

The 42-year-old, a former world player of the year, has yet to complete the full quota of practice hours with the French Football Federation to obtain the promotion to level three.

Zidane was elevated to reserve team coach at the beginning of this season following a single campaign as Carlo Ancelotti's assistant during their famous "decima" season that culminated with May's Champions League triumph.

However, the former playing genius has hardly set the world alight, losing five of his seven games in charge.

A Spanish coaching school, the Cenafe, has also submitted a complaint to the Spanish Federation against Real over of Zidane's coaching of the reserve team, claiming that they are using his assistant Santiago Sanchez's name on the teamsheet to bypass the regulations.

The case has sparked controversy in Spain with national team coach Vicente del Bosque telling Cope radio station that "everyone should have a coaching badge".

Rayo Vallecano coach Paco Jemez used tougher language, describing Real's actions as "shameful".

However, both Ancelotti and former Barcelona legend – as coach – Johan Cruyff have spoken out in support of Zidane.