Henson only joined Toulon as a medical joker in February following injury to Clement Marienval but the 29-year-old's time in the Top 14 has been clouded in controversy.
Despite making a try-scoring debut against Stade Francais, Henson hit the headlines for the wrong reasons after an alleged altercation with team-mate Matt Henjak.
The 2005 Test Lion was rumoured to have criticised fellow Lion Jonny Wilkinson and club captain Joe van Niekerk and was later suspended for a week as a result of the incident in a local nightclub.
The former Ospreys star, who had a brief spell with Saracens following an 18-month absence from the game, now looks set to have to find a new club after Toulon announced the signing of Rugby League convert Willie Mason.
An Australian international in the 13-man code, Mason is expected to play at centre, while Toulon have also signed Wallaby midfielder Matt Giteau for next season.
Henson was recently named in the Wales squad to face the Barbarians in Cardiff on June 4, his first international involvement in more than two years.
And if reports of his exit from Toulon are true, the Welsh Rugby Union could push for Henson to return home, with the Dragons having already signaled an interest.