Libya’s interim government, under mounting international pressure, said Monday that it will request an investigation of the death of Moammar Gaddafi, but authorities continued to insist that the former leader was not executed by revolutionary forces.

Speaking a day after declaring the country officially “liberated” from Gaddafi’s four-decade rule, Mustafa Abdel Jalil, head of the Transitional National Council, said the interim governing body has formed a committee to decide what to do with the corpse. A wounded Gaddafi was captured Thursday while trying to hide in a drainage pipe a few miles west of his final stronghold, Sirte. His body turned up hours later with a gunshot to the head.

The saga of what to do with Gaddafi’s body finally appeared to have come to an end Tuesday, after days in which the body was displayed in a frozen-food locker in the city of Misurata as thousands of people filed by to gape. A military spokesman in the city told the Associated Press that the bodies of Gaddafi, his son Mutassim and a top aide were buried at a secret location at dawn, with a few relatives and officials in attendance.

Because Gaddafi’s death was so popular in Libya, an impartial investigation of it is considered highly unlikely. Abdel Jalil did not give any details about who will conduct the inquiry.

Abdel Jalil, a justice minister under Gaddafi who is now effectively Libya’s interim president, also assured the international community on Monday that “we are moderate Muslims.” But he refused to back down from his surprise announcement Sunday that the country’s new laws will permit polygamy and ban the charging of interest on loans.

That declaration signaled that the anti-Gaddafi forces may steer their new democracy toward stricter Islamic rule. Such a move may cause concern in the NATO countries whose air campaign crippled Gaddafi’s forces and facilitated the revolutionaries’ victory. Confusion reigned Monday over exactly what kind of laws might be adopted, and the country appeared set for an extended debate on the issue.

In a news conference, Abdel Jalil continued to insist that Gaddafi was shot in crossfire, but he also suggested an alternative explanation: that Gaddafi was killed by loyalists to prevent him from being put on trial and implicating them in such crimes as executions, illegal arrests and corruption.

“Free Libyans were very careful and wanted Gaddafi to spend as much time as possible in prison,” he said. “Those who had an interest in his speedy death were those who supported him.”

In Misurata — where the remains of Gaddafi’s son Mutassim and former army chief, Abu-Bakr Yunis Jabr, were put on public display in a refrigerated meat locker along with his — officials ended the spectacle Monday as the corpses rapidly decomposed. With the door continually opening to allow thousands of curious Libyans to view the bodies laid out on filthy mattresses, the refrigeration failed to keep them from rotting, Reuters news agency reported. Guards handed out surgical masks and sprayed disinfectant over the corpses, to little avail.

Abdel Jalil said the transitional council has established a committee to determine what to do with the remains and will follow a religious ruling, or fatwa.

Cellphone videos taken after Gaddafi’s capture show revolutionaries kicking and punching the former leader, raising questions about whether they were the ones who killed him with a shot to the head. The government’s account that he died in a firefight after he was captured has not been substantiated.

In the aftermath of Gaddafi’s death, which followed the revolutionaries’ seizure of his final refuge in Sirte, the new Libyan government has come under strong international pressure to curb retaliation against defeated Gaddafi loyalists.

The New York-based group Human Rights Watch said Monday that 53 apparent Gaddafi supporters appeared to have been executed on the lawn of an abandoned hotel in Sirte last week. It said some had their hands tied behind their backs when they were killed, apparently between Oct. 15 and 19.

“This latest massacre seems part of a trend of killings, looting and other abuses committed by armed anti-Gaddafi fighters who consider themselves above the law,” said Peter Bouckaert, emergencies director at Human Rights Watch, who investigated the killings.

The group called on the Transitional National Council to “conduct an immediate and transparent investigation into the apparent mass execution and to bring those responsible to justice.”

The group also said that its investigators found at least 95 bodies at the site where Gaddafi was captured.

“The vast majority had apparently died in the fighting and NATO strikes prior to Gaddafi’s capture, but between six and ten of the dead appear to have been executed at the site with gunshot wounds to the head and body,” the group said in a report on its Web site. It said that authorities in Sirte have reported finding dozens of bodies of apparent reprisal victims.

In a speech at a massive gathering Sunday to celebrate victory in the eight-month revolt against Gaddafi, Abdel Jalil announced that the country’s new laws will more strictly adhere to Islamic principles. He reiterated Monday that banks will no longer be permitted to charge interest, because “Islam bans and forbids interest.” The Islamic banking system regards such payments as usury.

But officials gave widely varying versions of how the laws will change. Shamsiddin Ben-Ali, a senior media official with the Transitional National Council, said the new government will lift Gaddafi’s ban on Islamic banks but will allow Libyans the option of using interest-charging commercial banks.

At the moment, the council can barely enforce any law. Courts are hardly functioning, and armed militias still essentially control much of the country. Libyan society is already religiously conservative; drinking alcohol is prohibited, and most women wear head scarves.

Ben-Ali said any changes to Libya’s law will come after the writing of a new constitution, which will be overseen by a 200-member body chosen in elections in June. “A lot of Western-educated people will be on that committee” rewriting the constitution, he said.

But Abdel Jalil offered a more uncompromising vision, highlighting the divisions that are surfacing among those now running the country. He said he will give no ground on abolishing lending that involves interest payments. “There is an Islamic verse that cannot be negotiated or argued” on the issue, he said.

He also said current restrictions on polygamy should be lifted, because the practice is allowed by Islamic law. Currently, a man can take a second spouse if he receives approval from his first wife and assent from a judge.

The confusion about Libya’s future legal system could discourage some foreign businesses from investing at a time when new authorities are eager to get the economy functioning again and to create jobs.

Many Arab countries have constitutional language establishing Islamic sharia law as the basis for their legal systems, but the religious principles can be interpreted in a variety of ways.

With the war over, Abdel Jalil will preside over an interim government that is supposed to be formed in the next 30 days and lead the country to elections. His term will expire in June, but he is popular and may well play a prominent role in the country’s politics over the next few years, analysts said.

Branigin reported from Washington.