After six years with Toulon, Matt Giteau has announced he will leave the Top 14 heavyweight to play in Japan.

The 34 year-old has been integral to Toulon's recent success, the French side claiming three European Champions Cup titles in succession from 2013 to 2015, and winning a league and cup double in 2013-2014.

His move to France brought a temporary halt to his Australia career but he returned to the fold in 2015 as coach Michael Cheika introduced a new ruling - known as 'Giteau's Law' - that allowed players with 60 caps or more to play for the Wallabies despite leaving Super Rugby.

Since making his international debut in 2002, Giteau has collected over 100 caps and played in three Rugby World Cups - Australia finishing as runners-up in 2003 and 2015.

Giteau's French adventure will come to an end after this season with a move to Japan, although which club he will play for remains unclear.

"I want to announce that at the end of this season I'll leave to play in Japan," Giteau posted on Instagram. "This decision was the most difficult of my rugby career but it is the best for my family to be closer to Australia. 

"I want to say a big thank you to the players, which I made life-long friendship with, coaches, to the president and the staff behind the scenes since 2011. I owe a lot to you.

"I also want to say a big thank you to Toulon supporters who will stay in my heart for life. The time spent at Toulon was the best time of my rugby career.

"My principle objective now is to win titles for this historic club."