By Roger Hardy
BBC Middle East analyst
The official Syrian News Agency announced Ghazi Kanaan's suicide without attempting to explain it.
Kanaan (r) had a long and intimate connection with Lebanon
It said cryptically that the authorities were carrying out the necessary investigation.
But, given Mr Kanaan's long and intimate connection with neighbouring Lebanon, many will regard his death as suspicious and will link it to the killing of former Lebanese Prime Minister Rafik Hariri in February.
The Hariri saga is becoming more and more like the plot of a bizarre political thriller.
The assassination prompted immediate suspicion of Syrian involvement given its dominant position in the life of its tiny neighbour, and strenuous denials from Damascus.
But from Syria's point of view, it has brought nothing but trouble.
The killing of Hariri led to Syria's international ostracisation and to mass political protests in Lebanon.
The combination of the two forced the Syrians to make a humiliating military withdrawal from a country it had occupied for almost 30 years.
Worse still, it antagonised the Bush administration in Washington, already angry over Syria's alleged support for insurgents in Iraq.
Many will now suspect that Ghazi Kanaan was a sacrificial lamb, who is now conveniently out of the way ahead of the UN report into the death of Mr Hariri which is due to be published later this month.
The Hariri killing and its aftermath are posing a serious challenge to Syria's President Bashar al-Assad.
If the UN report were to implicate senior Syrian officials - people close to the president - Syria would become even further isolated and face the possibility of UN sanctions.
And there are some in Washington who would seize the opportunity to press even harder for something they have always wanted - "regime change" in Damascus.