Springbok prop Tendai "Beast" Mtawarirahas questioned whether former national coach Peter de Villiers was competent for the role he occupied between 2008 and 2011.

Mtawarira, who made his Springbok debut under De Villiers' guidance in 2008, made the startling revelation in his new autobiography, Beast, which will be on sale from July.

"He was a fantastic coach of the Junior Springboks, but I think at the high level he was probably lucky that a very good group of players was handed over to him," Mtawarira writes in the book.

Mtawarira was referring to the fact that De Villiers had inherited Jake White's 2007 World Cup winning team with senior players like Victor Matfield, Fourie du Preez, Schalk Burger, John Smit, Bakkies Botha, Danie Rossouw, Jean de Villiers, Jaque Fourie, Bryan Habana and JP Pietersen ruling the roost.

Mtawarira added: "His methods and approach didn't really work with the Springboks, and as players we had to be careful what we said to the media. What you said would get back to Peter and affect your place in the team. The media did not like Peter and thought he was a bit of a clown.

"There's no doubt that he was happy to be at the forefront of a team that could operate on its own steam. Most of the work was done by the players, with (assistant coaches) Dick (Muir) and (Gary) Gold very influential."

During his tenure as Springbok coach, De Villiers won five out of 11 Tests against the All Blacks - a better record than most Bok coaches in recent times.

Other notable achievements for De Villiers as Bok coach was a Tri-Nations win in 2009, as well as a series win over the British and Irish Lions that same year.