Belgium's regional government of Wallonia came under fire on Monday for authorising the sale of weapons to Libya in 2009, prompting a probe into whether the arms were used against protesters.

The governments of the French-speaking region asked the Belgian ambassador in Tripoli to ask Libyan authorities how the weapons have been used, said Christopher Barzal, spokesman for Wallonia's regional leader Rudy Demotte.

Wallonia gave an export license to Liege-based FN Herstal for the sale of 367 F2000 assault rifles, 367 P90 submachine guns, 367 Five-Seven handguns, 20 Minimi light machine guns, 22,000 rifle grenades and 1.134 million rounds of ammunition for these weapons, for a total value of 6.9 million euros.

The license also authorised the sale of 2,000 FN 303, a compressed-air gun that fires projectiles which, according to the firm's website, can be used to stop a "hostile but unarmed individual or group" among other things.

The sale of these so-called "less-lethal" weapons was valued at 5.3 million euros.

The final use certificate states that the weapons are for the exclusive use of the Libyan army's 32nd elite forces battalion for a mission to protect "humanitarian aid convoys to Darfur", Barzal said.

The Belgian Human Rights League expressed fears that the weapons could have been used by the regime of Libyan leader Moamer Kadhafi to repress anti-government protests, but it admitted it had no proof.

"The probability is very low, but we have asked the ambassador to verify urgently," Barzal said.

The European Union lifted an arms embargo on Libya in 2004.

In Belgium's decentralised political system, the regions are responsible for approving licenses for arm exports.