Ali Mamlouk: another man who knew too much?

Syria's security chief, Ali Mamlouk, is rumoured to have been killed by the Syrian regime.

If true, he is the latest of several Syrian spymasters to have died after being linked to the assassination of Lebanese prime minister Rafik Hariri.

Other Syrian intelligence chiefs linked to the murder have also died or disapeared.

Rustum Ghazaleh, the head of the National Intelligence Agency, died from injuries suffered in a brawl with Rafik Shehadeh from the army's intelligence branch.

Ghazaleh was rumoured to be on the verge of announcing revelations about the Hariri case before he died.

Ghazi Kanaan, a former interior minister, was also linked to Hariri's assassination and died under suspicious circumstances. Officially he committed suicide.

Jameh Jameh, the head of military intelligence in Deir ez-Zor, died in 2013 after being accused of involvement in Hariri's killing.

Assef Shawkat, Bashar al-Assad's brother-in-law, was killed in a bombing that targeted a Syrian cabinet meeting - and again was said to have information on the Hariri case.

Syria's official news agency has dismissed the rumours and said that Mamlouk was in good health and still at his work.

Amir Mousavi, a journalist with close links to the Iranian regime, posted on Facebook that Mamlouk was ill with high cholesterol "as a result of overeating".

Reports suggest that the regime have already found a replacement for Mamlouk - Tawfiq Haidar, from the air force intelligence's "special division".

If true, he too might be nervous that he could meet the same fate as his predecessor.

This article is an edited translation from our Arabic edition.