Toulon have now announced the capture of the Wales back who will join Philippe Saint Andre's men with immediate effect.
Henson has signed a two-and-half year deal which will run up until the summer of 2013.
"Wales international Gavin Henson has signed a contract at Toulon as a 'medical wildcard' for Clement Marienval," read a statement on the official Toulon website.
The move is expected to give Henson an early chance to play fly-half - the position he stated he wished to be considered in for Sarries - as Jonny Wilkinson is away on Six Nations duty and Felipe Contepomi is out injured.
However, Henson himself is currently sidelined with a calf injury, a setback which saw him miss out on potential selection for the Six Nations.
If Henson can find his form and fitness in the coming weeks he may yet be added to the Wales squad for the latter stages of the Six Nations and it is thought the 29-year-old has received clarification from Toulon that his international career will not be hampered by any club versus country rows.
Toulon appear to have agreed to release Henson for any possible international duty both in the Six Nations and for the 2011 World Cup in New Zealand.
Henson joins fellow Welsh Lions James Hook and Lee Byrne in agreeing a switch to France after Hook signed for Perpignan and Bryrne signed for Clermont Auvergne.