African footballers as young as 14 are being trafficked to Asia and forced to sign contracts, the BBC has learnt.
Six minors are still with top Laos side Champasak United, after it imported 23 under-age players from West Africa to an unregistered football academy in February, a BBC investigation found.
Fifa regulations prohibit the movement of players to a foreign club or academy until they are 18.
The club, based in the southern city Pakse, denies any wrongdoing.
"Fifa is in contact with several member associations in order to gather all information to assess the matter and safeguard the interests of the minors," a Fifa spokesperson told the BBC.
Global players' union body FIFPro, which helped release some of the 23 players three months ago, said in a statement it 'suspects this case is not one of its kind, but probably the tip of the iceberg'.
It has been claimed that Champasak United, a newly-formed club which plays in Laos's top league, intends to profit by selling the players in future.