"Joe did inform me that, because he was not offered a Springbok contract, he wanted to go play overseas," Eugene Eloff told iafra.com.
"So there could well be a measure of truth in that report."
Eloff signed van Niekerk when the former Stormer player's career appeared to be on the slide following the downfall of a proposed move to Northampton Saints.
Van Niekerk had agreed a deal to join the English club but that agreement was never fulfilled due to concerns regarding his fitness.
Now, Eloff has hinted that one of his star players could be keen to rekindle a move abroad, with big-spending Toulon a possible destination.
"I don't know if anything has been officially agreed, but I know that Toulon did speak to him.
"It would probably be sorted out after the Tri-Nations."
Although, a number of fringe players are set to depart South Africa at the end of the Currie Cup season, van Niekerk's possible departure would buck a trend of established internationals returning home in time to face the Lions.
The likes of national captain John Smit and 98-times-capped full back Percy Montgomery have rejoined South African provinces following successful stints in France but, despite the presence of Pierre Spies and Ryan Kankowski, the absence of his first choice No8 would be of undoubted concern to Springbok coach Peter de Villiers.