In the 10 days since his flag-draped coffin was paraded through Liberation Square here, solving the killing of Gen. Abdul Fattah Younis has emerged as the most crucial test of the young rebel government, perhaps as important as fighting Libyan strongman Moammar Gaddafi.

“This is a critical moment for the revolution,” said Fawzi al-Waniss, a former oil company engineer who serves as commander of a security brigade that patrols the streets of Benghazi.

The assassination of one of the most potent and polarizing symbols of the Libyan uprising has shaken domestic and international confidence in the Transitional National Council, the fractious body of unelected lawyers, businessmen and expatriates that the Obama administration last month recognized as the sole legitimate government of Libya.

As conspiracy theories race through coffee shops, the unsolved killing of the rebel military chief reinforces Benghazi’s image as a lawless, chaotic rebel capital where dozens of armed militias are only now being brought under centralized control.

The mystery has had repercussions: A group of lawyers instrumental in the uprising recently began calling for the resignations of top rebel officials for their alleged roles in ordering Younis’s arrest.

Since his burned and bullet-ridden corpse was found dumped in a ditch near his home, the leaders of the transitional government have offered very little, and often contradictory, information about the general’s final hours.

“This case is so sensitive, so important, so central, for our revolution,” said Jamal Bennour, a judge in Benghazi involved in investigating the death. “We know this is an urgent case.”

Unraveling the murder mystery — which Libyans compare to the JFK assassination — looms as a major test of the rebels’ professed belief in justice, transparency and rule of law.

In Benghazi, talk of Younis has replaced news of the stalled rebel advance in the oil town of Brega and complaints about delayed salaries.

At a news conference Saturday, the titular head of the Transitional National Council, Mustafa Abdel Jalil, promised that civilian investigators had begun their inquiry, “with results very soon.” He thanked foreign backers for their continued support and stressed that the rebel leadership had nothing to do with Younis’s killing.

“Revolutionary elements would never commit such an act, especially at such a critical time,” Abdel Jalil said. “And when I said General Younis is a victim of conspiracy, I mean that the persons who committed such a crime have a relationship with Gaddafi.”

Abdel Jalil offered no proof.

Patience among Younis’s supporters and members of his powerful tribe has grown thin. “We want to give the transitional government council a message that they need to give us answers,” said Abdel Fattah Ali, a long-serving special forces soldier loyal to Younis. He came to pay his respects Thursday at the mourning tent at the general’s family compound in a Benghazi suburb.

“He wasn’t killed at the front line, which would have been a different matter,” Ali said. “His death was an act of betrayal.”

Or an act of revenge. Or an assassination. Or an execution. With each passing day, new suspects and theories emerge to suggest that Younis was killed by elements loyal to Gaddafi, or by rivals in the rebel movement, or by Islamist extremists, or by “fifth columnists” who receive their marching orders from Tripoli via coded messages on state TV.

Younis was undeniably a controversial figure. He was Gaddafi’s interior minister and longtime confidant when he defected with great fanfare in February and led the military campaign against Gaddafi forces.

One of the last men to see the general alive said he watched Younis being placed under arrest by hundreds of his fellow fighters the morning of July 28. They came in 60 cars, the witness, Ali Ibrahim, said. The men were hostile and armed. “Younis was taken away before dawn,” Ibrahim said. “The men surrounded the compound and said they had strict orders to bring him back to Benghazi.”

Then the general vanished.

The head of the Transitional National Council said Younis was being brought back to Benghazi to answer questions from a military panel. “We had received reports from the front lines of gaps and shortcomings,” Abdel Jalil said. “Before he was brought to the office, he was assassinated.”

The next day, the rebels’ oil and finance minister, Ali Tarhouni, said members of the little-known Abu Obaida al-Jarah brigade had arrested Younis, and he suggested that they were responsible for the killing.

A few hours later, the rebels’ military spokesman, Ahmed Bani, told reporters not to pay too much attention to the minister.

Then the spokesman said he was reluctant to discuss the case with journalists, suggesting that they might not be who they appear to be: “We don’t know if anybody here is a fifth column.”