I believe this reporter has denied saying that.
That's not true. He registered his declaration to a Belgian judge.
The former hostage told several media in the wake of his return to Belgium, he had revelations to make on the use of chemical weapons in Syria. "It is a moral duty to tell. This is not the government of Bashar al-Assad has used sarin gas or other fighting in the suburbs of Damascus. We are sure after a conversation we have surprised (between the rebels) "
http://www.lalibre.be/actu/international/syrie-pierre-piccinin-aurait-des-revelations-a-faire-sur-l-usage-d-armes-chimiques-522dde7035702bc05f0c2e10
The post 6 from Margeurite seems to agree with the assertion in the Free Syria Press. Do you have some evidence you can post?