Rugby greats have taken to Twitter to express their disbelief and their sympathies over the death of former All Black Sione Lauaki.

Sonny Bill Williams tweeted "it's a sad day today, rest east dox" whereas Piri Weepu's tweet showed a reaction of heartbreak and crying emojis to the news.

Sione Lauaki. Source: Getty

The former All Black flanker and number 8 has died at the age of 35, his family has confirmed.

1 NEWS understands Mr Lauaki suffered kidney problems.

Lauaki made his debut for the Chiefs in 2004 before earning an All Black call-up in 2005. He played 70 Super Rugby matches and was capped 17 times for New Zealand.

Leaving for French Top 14 side Clermont Auvergne in 2010, Lauaki made the move to Bayonne in 2011.

Lauaki made a name as a back-rower alongside the likes of Rodney So'oialo and Jerry Collins.

In 2012, during routine tests, Lauaki was dignosed with significant kidney and cardiovascular problems, leading for him to be released by Bayonne, Newshub has reported