Domenico Quirico, an Italian journalist, and Pierre Piccinin, a Belgian teacher, disclosed a grim account of their captivity in Syria as well as potentially new information about the chemical weapon attacks, upon their return to Rome Sunday.

As a seasoned war correspondent, Quirico traveled to Syria by means of Lebanon on April 6 to cover the revolution. Three days later, Quirico and Piccinin were kidnapped as they traveled to the Syrian city of Homs together.

Held hostage for six months, Quirico and Piccinin claim to have overheard their captors through closed doors, discussing the chemical weapon attacks near Damascus. Piccinin reports that the rebels said that Assad was not responsible for the attacks.

"It wasn't the government of Bashar al-Assad that used sarin gas or any other gas in Ghouta," Piccinin revealed on Belgian RTL radio.

"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 said.

But Quirico said the information cannot be officially verified and thus can only be regarded as conjecture.

Quirico told La Stampa, the Italian newspaper for which he reports, "We heard some people we didn't know talking through a half-closed door. It's impossible to know whether what was said was based on real fact or just hearsay."

"You must bear in mind the conditions in which we were; we were prisoners and heard things through doors," he added.

Both can agree on one thing: their conditions were "terrifying," a fact that their physical appearance seems to corroborate, according to reporters who witnessed their homecoming.

"I was treated badly," an exhausted Quirico told reporters. Piccinin said they faced mock executions and "real violence."

It is believed the two men were originally kidnapped by the Free Syrian Army and then transferred to a rebel group known as the Abu Ammar brigade.