New Zealand rugby league convert Sonny Bill Williams has extended his contract at French Top 14 side Toulon by one season, the rugby club announced.

The 23-year-old centre sparked a media storm when he left Australia mid-season last year to switch codes and play in Europe, despite being only one year into a five-year contract with the NRL's Bulldogs.

Toulon had hoped to tie Williams to the club for at least two more seasons, but finally agreed to an extension of just one year.

After an injury-plagued start to his career in France, Williams has since performed impressively, featuring in 11 matches and scoring two tries.

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