Colombian guerrilla leaders convicted of war crimes or crimes against humanity could get suspended sentences if government and rebel negotiators reach a peace accord, an official said Monday.

The two sides have been negotiating in Havana since late last year to try to end Latin America's last and longest insurgency, one that has ground on for nearly 50 years and claimed an estimated 600,000 lives.

Most of the leaders of the leftist rebel group FARC have already been tried and convicted in absentia of a variety of crimes, but none for crimes against humanity or war crimes.

However, attorney general Eduardo Montealegre said authorities continue to investigate whether any can be charged with such offenses.

And if they were charged and ultimately convicted, such sentences might be suspended if the peace talks in Havana yield an accord, Montealegre said in an interview with the newspaper El Tiempo.

It is the Congress which would have decide if this were possible, he said.

"It is a political decision which Congress would have to take at that time, but nothing is decided yet," he was quoted as saying.

Last year the legislature passed a constitutional reform that allows for suspended sentences and other forms of leniency for rebel leaders if a peace accord is reached and the FARC lay down weapons.

Suspended sentences should also be considered for army personnel convicted of human rights violations, the attorney general said.

"If we want to build stable and lasting peace, we have to include all parties to the conflict," he said.

Besides the estimated 600,000 dead, the conflict in Colombia has left more than 3.7 million people internally displaced because of the violence.