Damascus Attorney-General Mohammed al-Loji said forensic examinations and a probe of his office had concluded that he shot himself in the mouth with his own pistol in his office on Wednesday.
Al-Loji "announced the end of the inquiry into the circumstances of the death of Ghazi Kanaan after technical procedures were carried out and the body was examined by three coroners", Syrian Arab News Agency (Sana) reported.
"It was established that the cause of death was suicide using General Kanaan's personal revolver, a .38 calibre Smith and Wesson," it said, a day after an official announcement that he had committed suicide in his office.
"Examination of the body and finger prints as well as testimony from (the minister's) employees, including senior aide General Walid Abaza, indicated that it was a suicide by gunshot. General Kanaan put the barrel of his gun in his mouth and fired a bullet."
The attorney-general said Kanaan's assistant had heard a faint shot and entered the major-general's office to find him lying on the floor behind his desk, still breathing, with his pistol in his hand. He died in hospital.
Syrian newspapers reported Kanaan's death on their front pages but ventured no motive for his apparent suicide, three weeks after he was questioned by UN investigators probing the assassination of Lebanese former Prime Minister Rafiq al-Hariri.
In line with the tradition of Syria's state-controlled media, dailies gave prominence to remarks by President Bashar al-Assad, this time a CNN interview in which he said Syria was not involved in al-Hariri's killing and that he could never have ordered it.
Kanaan's funeral procession
leaving a Syrian hospital
Meanwhile, Druze MP Walid Jumblatt, who is also leader of Lebanon's Progressive Socialist Party, said at a media conference on Thursday that Kanaan was opposed to extending Lebanese President Emile Lahoud's term in office.
"He was betrayed by his close aides," he said.
However, Jumblatt added: "If Kanaan felt he was responsible for the assassination of al-Hariri, he has done well by committing suicide."
Already under pressure from the US, which accuses it of allowing fighters into Iraq, Syria has grown increasingly nervous over Lebanese and international charges it is linked to al-Hariri's death.
In his first reference to the possibility that Damascus might cooperate with a potential international tribunal into al-Hariri's murder, al-Assad told CNN if the killing was carried out without his knowledge the culprit would be tried for treason.
"If it happened then it's treason," al-Assad said, hours before news of Kanaan's death broke.
"If (Syrians) are implicated they should be punished. International (court) or Syrian, whatever."
On Thursday, an ambulance adorned with flowers took Kanaan's body from the private Shami hospital in central Damascus to his birthplace of Bhamra, in northern Syria, where he was to be be buried later in the day witnesses said.
Al-Assad: If Syrians are involved
they should be punished
Senior military and security officials along with Prime Minister Naji al-Otari and Foreign Minister Farouq al-Shara were present at the hospital to pay their respects before the body left in a convoy of cars for his final resting place.
The military officers stood to attention as Kenaan's four sons carried their father's coffin to an ambulance for the journey to Bhamra.
The Syrian flag was notably absent from the coffin of Kanaan, but a wreath from the president's office was fixed to the front of the ambulance.
Looking visibly shaken, al-Shara said some media outlets had pushed Kanaan to commit suicide.
He was referring to reports appearing in Lebanese newspapers since al-Hariri's death. Al-Sharaa said he was sure the UN report would find Syria innocent of al-Hariri's killing.
Rafiq al-Hariri (R) was killed in a
bomb attack earlier this year
Around an hour before he died, the 63-year-old called Voice of Lebanon radio to apparently give his last testimony, denying a media report that he had shown investigators photocopies of cheques signed to him by al-Hariri and defending Syria's role in Lebanon, where it kept troops for 29 years until April.
Kanaan was the head of Syrian military intelligence in Lebanon from 1982 until 2002. He was appointed interior minister in 2004. In 2002, he was appointed as chief of the Syrian Political Security Directorate.
Syria was the main powerbroker in Lebanon after the end of its 1975-1990 civil war. It was forced to relinquish its grip amid international and local uproar over al-Hariri's killing.