Brig. Gen. Jamil Sayyed was among four pro-Syrian officers who were jailed without charge for nearly four years in the 2005 assassination of Hariri's father, Rafik. They were freed last year for lack of evidence.

In a news conference Sunday, Sayyed accused Hariri of selling his father's blood to frame Syria for the killing, which at the time set off a wave of turmoil that led to the withdrawal of Syrian troops after nearly 30 years.

Sayyed, who left the country shortly after his remarks, also said Hariri supported “false witnesses” who misled the investigation into his father's death.

Sayyed warned Hariri that he must be held accountable or “I will do it someday with my own hands.” He later said he meant he would get justice through the courts.

“The Lebanese people must unite against this (government) and topple it, even if by force,” Sayyed said.

Prosecutor General Said Mirza summoned Sayyed for questioning over his “threats against the Lebanese state” and Hariri, the judicial official said. He spoke on condition of anonymity because he was not allowed to give official statements to the media.

Rafik Hariri, a billionaire businessman and former prime minister, was Lebanon's most prominent politician after the end of the 15-year civil war in 1990. Suspicion initially fell on Syria after the killing in February 2005, since Hariri had been seeking to weaken Damascus' domination of the country.

Syria has denied having any role in the killing and last week, in a stunning reversal, Hariri's son said it was a mistake to blame Damascus.

Earlier this year, Sayyed asked the UN tribunal investigating Hariri's assassination to release his secret case file so that he might know who accused him. Sayyed traveled to Paris following his press conference on Sunday to await the court's decision, which is expected this month.

The judicial official said if Sayyed did not respond within the coming 48 hours, his name would be distributed on all ports of entry in Lebanon so that he can be taken for questioning upon arrival.