South African musician Ard Matthews has apologised after bungling the national anthem on live television on Tuesday.

Although Matthews's rendition of Nkosi Sikelel' iAfrica was not nearly as horrendous as the 2009 version of French-based South African Ras Dumisani, Matthews' faux pas on Tuesday still caused a national outcry.

And, to his credit - unlike an unapologetic Dumisani in Toulouse in 2009 - Matthews owned up and apologised for his mistake.

"Seriously, I am utterly devastated," Matthews posted on the social network Twitter, after being criticised for his performance in Johannesburg during the announcement of the Springbok squad for next month's World Cup.

"This was a huge honour for me and I could not be more embarrassed and sorry."

Barry Tuck tweeted: "What was that song Ard Matthews just sang? I didn't recognise it."

Shaun Gray wrote: "Ard Matthews pulling a Ras Dumisani - Priceless," referring to the reggae singer's off-key mutilation of Nkosi Sikelel' iAfrica before the Springboks' game against France in 2009.

In a statement issued by SuperSport later, Matthews was quoted as saying: "I've sung it my whole life and was overcome with emotion. It wasn't intentional... I support everything about this whole country.

"This was the worst moment of my life. I was so frozen and nervous and my nervousness came out as a laugh. This was no attempt at humour, but a nervous response to an awful situation."

Springbok captain John Smit accepted the apology.

"This was like a Test debut for him. He was so excited to be doing this. Mistakes happen. Nothing I said could make him feel better," he said.

SuperSport spokesman Clinton van der Berg said the channel was equally embarrassed and that it was in no way a reflection on South African rugby.

Matthews founded the rock band Just Jinjer (formerly Just Jinger) and is based in California in the United States.

SAPA

* Who was the worst?

Ard Matthews - 2011:

Ras Dumisani - 2009: