CNN is investigating the identity of a man the US broadcaster showed being rescued from a Syrian jail as he may have given a “false identity”.

The investigation was launched amid claims he was a member of Bashar al-Assad’s forces.

The man, found under a blanket in a prison in Damascus by Clarissa Ward, the broadcaster’s chief international correspondent, claimed he had been arrested three months ago and interrogated about his phone contacts.

The footage was described as “remarkable” by CNN’s head of communication at the time, praising Ward and her team for finding “a Syrian prisoner left behind in a secret prison, alone and unaware the Assad regime was no more”.

He gave his name as Adel Ghurbal and said he was taken from his home in the city of Homs to the Syrian capital by the intelligence services.

Verify-Sy, a Syrian fact-checking organisation, later claimed that his real name was Salama Mohammad Salama and that he was a first lieutenant in Syrian air force intelligence.

He managed several security checkpoints in Homs and was involved in theft, extortion and coercing residents into becoming regime informants, it claimed.

Verify-Sy also alleged the man had killed civilians, detained or tortured numerous young men on fabricated charges, and taken part in military operations in 2014, when Assad’s forces seized Homs from Syrian rebels following a three-year siege.