It hasn't taken much for Sonny Bill Williams to grab the test spotlight after rugby fans questioned why he didn't sing the New Zealand anthem at Eden Park.

The big No 12, returning to the test side after a stint in the Mitre 10 Cup, stayed silent through the Māori and English versions of God Defend New Zealand before the Bledisloe Cup mauling of the Wallabies.

Williams has not been afraid to use his platform for protest, famously refusing to wear a bank logo on his Blues jersey.

NFL player Colin Kaepernick began a sporting movement three years ago, when he sat and kneeled during the American anthem in protest at racist police violence.

Sonny Bill Williams of the All Blacks stands for the national anthem. Photo / Getty Images.
Sonny Bill Williams of the All Blacks stands for the national anthem. Photo / Getty Images.

As yet there has been no reason given for Williams staying mum during the anthem, with social media users left to speculate.

Halfback TJ Perenara wore a "Ihumātao" wrist band in support of the protestors at an Auckland housing development site during Bledisloe Two.

The Ihumātao protest is an occupation of the land near the protected Ōtuataua Stonefields in Māngere, in opposition to the housing development planned by Fletcher Building.

Coach Steve Hansen brushed off Perenara's decision after the test saying: "It's his decision, it doesn't bother me. I didn't even notice it, to be honest. They write all sorts of stuff on their wrist bands these blokes today. I don't know what I'd write on mine if I had one."

One social media post asked if Williams, who has Samoan heritage, was also supporting the Ihumātao protestors.

Three years ago, New Zealand Māori prop Kane Hames wore a "Standing Rock" wristband in support of the indigenous people in North Dakota, USA.

Then, New Zealand Rugby, which has set guidelines around what players can and cannot write on their apparel during matches, stopped short of telling him not to do it again.

At the time, then NZR general manager Neil Sorensen said: "There's an expectation that staff and players do not involve themselves in conduct that may bring their employer, and the game, into disrepute."