A Belgian writer held hostage for five months in Syria has said that his own rebel captors denied that President Bashar al-Assad was responsible for the Ghouta massacre.
Pierre Piccinin said that he and fellow hostage Domenico Quirico, an Italian war reporter, heard their jailers talking about the chemical weapon attack and saying that Assad was not to blame.
Quirico confirmed to La Stampa newspaper that they had eavesdropped such a conversation through a closed door but added that he had no evidence to substantiate what he heard.
Piccinin said the captives became desperate when they heard that the US was planning to launch a punitive attack against the regime over the gas attack in the Damascus suburb.
"It wasn't the government of Bashar al-Assad that used sarin gas or any other gas in Ghouta," Piccinin told Belgian RTL radio after he was released.
"We are sure about this because we overheard a conversation between rebels. It pains me to say it because I've been a fierce supporter of the Free Syrian Army in its rightful fight for democracy since 2012," Piccinin added.
"We were prisoners, stuck with this information and unable to report it," he said.
However, his fellow prisoner said it would be "madness" to say that he knew for sure that Assad was not culpable.
"I do not know if this is true but nothing tells me it is," he said.
Quirico said he listened to a Skype conversation between three individuals, whose names he could not confirm. One identified himself as a Free Syrian Army general.
The three contended that insurgents had used gas in Ghouta to trigger Western intervention.
"I have no evidence to confirm this theory and I do not know who these people were or if they are reliable," Quirico said.
"It is impossible for me to say if this conversation was based on real events or on rumours and hearsay. It is not my habit to hold true conversations overheard through a door."
Kidnapped in April, Piccinin and Quirico were freed by their captors and flown to Rome.
Quirico said he was treated badly. The Syrian revolution had turned into something "very dangerous" since he began covering it, he added.
Piccinin said for "ethical reasons" he would not release further details about what he had learnt while in captivity before Quirico had spoken to the Italian government and his newspaper La Stampa had made a decision on publishing the story.
Piccinin said they were taken hostage by members of the Farouq Brigade. No official details have been released on who was holding them or how they were released.
US secretary of state John Kerry gave an ultimatum to Assad to turn all his chemical weapons within the next week to avoid a strike against his regime.
According to Washington, strong and incontrovertible evidence indicated that the regime was responsible for the chemical attack in which 1,429 people died.