Rugby: Sonny Bill Williams logo snub - Blues left in the dark

Sonny Bill Williams of the Blues makes a break during the round seven Super Rugby match between the Highlanders and the Blues. Photo / Getty Images.

The Blues are unaware why Sonny Bill Williams covered up a sponsorship logo on his playing jersey during last night's Super Rugby match against the Highlanders and plan on taking the matter up with Williams' manager Khoder Nasser.

Williams had only been back on the field for a matter of minutes before creating a social media stir by covering up the BNZ logo on his Blues jersey's collar with medical tape.

Blues assistant coach Steve Jackson said he was surprised by the act and his team would be addressing it with Williams' management this week.

"The sponsors pay our wages and you look to do everything you can to make them happy, so I'm not really sure what occured or what's really happened," Jackson told Newstalk ZB's Tony Veitch.

The mysterious move sent social media into a flurry, with hundreds of Twitter users asking why?

How come #SonnyBillWilliams can blank out #Blues sponsor pic.twitter.com/zsTaXHKVUc

— Janice Miller (@JCMLOGS) April 8, 2017

The powerful 31-year-old midfielder is the only Blues player on the field to have covered the BNZ logo.

This is Williams' first 15s rugby game since the 2015 Rugby World Cup final.

Williams suffered an Achilles injury during the New Zealand Sevens team's opening pool match at the Olympics against Japan in Rio de Janeiro eight months ago.

The Herald have contacted the Blues for comment this evening.

Williams' manger Khoder Nasser said he is yet to discuss the decision with the player.

Why has #SBW covered up the BNZ collar logo maybe he banks with Westpac? #HIGvBLU

— John Sunde (@johnsunde) April 8, 2017

#HIGvBLU #SBW covering the BNZ logo on his jersey maybe something to do with Islamic beliefs on banks? No interest allowed to be paid, etc..

— Jeffrey Calmeyer (@TheNomadicNativ) April 8, 2017

Is Sonny Bill not allowed to advertise BNZ?? #HIGvBLU

— Brendon Trass (@brendontrass) April 8, 2017

Williams converted to Islam in 2009, a religion which frowns upon borrowing money or paying interest to banks.

The rules surrounding money lending lie in the principles of Islam's shariah law.

As a matter of faith, a Muslim is not allowed to benefit from lending or receiving money, meaning earning interest is disallowed.

Boxer Anthony Mundine borrowed $500,000 from Williams before his fight against Danny Green in February, to deal with a family emergency, the Daily Telegraph reported.

The deal was sealed with little more than a handshake between two long-term friends.

Mundine gave the Blues player $750,000 in 2008 when he stormed out from the Canterbury Bulldogs to play French rugby union.

A BNZ spokewoman said the bank had no issue with their logo being covered up.

"It's really between him and the Blues - we've got no issue with it," she said.

"He's entitled to have religious beliefs and customs around that and it's really between him and the Blues as to how that manifests itself. So we have no issue with it."

Williams is not the first sports star to have refused sponsorship on his uniform.

Pakistani-born Australian cricketer Fawad Ahmed has refused to wear the team's shirt which had a VB beer logo on it. Australian batsman Usman Khawaja followed suit and had his cricket gear modified to not show the VB or XXXX beer logos, according to The Courier Mail.

Prior to tonight's match Williams shared a photo of his jersey on social media. The personalised jersey is embroidered with the names of his wife Alana and two daughters Imaan and Aisha.