Four-week ban for Sonny Bill Williams

Sonny Bill Williams has been banned for four weeks following his red card in New Zealand's second-Test defeat to the British and Irish Lions in Wellington.

The cross-code star was sent off with just 25 minutes on the clock during Saturday's match, after catching Lions wing Anthony Watson flush on the head with a shoulder charge.

All Blacks coach Steve Hansen confirmed Williams would plead guilty to a charge of unnecessary contact with the head when he faced a hearing at the New Zealand Rugby offices in Wellington on Sunday.

That hearing resulted in a four-week suspension being imposed on the centre, whose place in the All Blacks' squad for next weekend's decisive third Test has been taken by Malakai Fekitoa.

"Just finished my hearing, ended up getting four weeks," Williams was quoted as saying by stuff.co.nz.

"Obviously really disappointed, but happy with being able to get in there and say my piece."

Williams is the first All Black to have been dismissed in a Test match for 50 years.