Ghana’s most influential witch doctor has claimed he is responsible for Christian Ronaldo's knee injury which is threatening the Portuguese star's participation at the 2014 FIFA World Cup.

Nana Kwaku Bonsam says he put a curse on the Real Madrid forward in order to prevent him playing against Ghana in the final round of their Group B game on 26 June.

Bonsam – whose name translates as "Devil of Wednesday" – claims the injury Ronaldo is currently suffering was "spiritual" and "can never be cured by any medic".

A statement from the Portuguese FA on Wednesday confirmed that Ronaldo is suffering from tendinosis in his left knee as well as nursing a muscle problem in his left thigh, which caused him to miss the 0-0 draw with Greece at the weekend.

“I know what Cristiano Ronaldo’s injury is about, I’m working on him,” the witchdoctor told Ghanaian radio station Angel FM.

“I am very serious about it. Last week, I went around looking for four dogs and I got them to be used in manufacturing a special spirit called ‘Kahwiri Kapam’.

“I said it four months ago that I will work on Cristiano Ronaldo and rule him out of the World Cup or at least prevent him from playing against Ghana and the best thing I can do is to keep him out though injury.

“This injury can never be cured by any medic, they can never see what is causing the injury because it is spiritual. Today, it is his knee, tomorrow it is thigh, next day it is something else.”

Portugal is slated to play Ghana in its final Group G matchup on June 28.