A major US broadcaster Fox News has apologised to viewers over Robbie Williams's behaviour.

The British singer showed his middle finger to the camera as he performed some of his greatest hits during the World Cup opening ceremony.

As the show was watched live by literally billions of spectators all over the world, many people expressed their dissatisfaction with the 44-year-old’s behaviour.

While it remains unclear who Williams’ obscene gesture was addressed to, Fox News, who was broadcasting the opening ceremony, issued an apology to their viewers.

“As it was broadcast live, we did not know what would happen during Robbie Williams's performance and we apologise,” Fox’s spokesman said.

The former Russian figure skater Ilya Averbukh, who was the choreographer of the World Cup opening ceremony, has his own ideas about Williams’ gesture. “I’d regard it an answer to all sceptics who criticised him in his country. I’m sure it has nothing to do with us or Russia. I think he could show his strength by doing that - after all, Robbie is a big star and has a right to do whatever he finds necessary,” he said.