BOGOTA (Reuters) - Officials from the special Colombian tribunal tasked with trying crimes related to the country’s five decades of conflict may have covered up the non-compliance of several former rebel commanders with a peace accord, the attorney general said on Friday.

The Special Jurisdiction for Peace (JEP) tribunal, founded under a 2016 peace deal between the government and Revolutionary Armed Forces of Colombia (FARC) rebels, will try cases considered representative of the war’s violence and mete out sentences to ex-guerrillas, paramilitaries and government soldiers convicted of war crimes and human rights violations.

Some tribunal staff have hidden that former rebel commanders are not following the terms of the accord, attorney general Nestor Humberto Martinez said.

“The attorney general’s office has evidence that some unscrupulous officials are cooking up falsehoods and procedural fraud so the Special Jurisdiction for Peace won’t act as it should,” Martinez said. “We have opened an investigation by a special prosecutor that will produce decisions shortly.”

Martinez did not name the officials or the ex-commanders they are alleged to have helped. But his comments came one day after the U.N. Verification Mission in Colombia, which manages rebel reintegration zones, said six former commanders were failing to fulfill their obligations under the accord and had left the camps.

The six include Hernan Dario Velasquez, known by his nom de guerre El Paisa, and Henry Castellanos, known as Romana, a source who works at an organization closely following the peace process said.

Velasquez was convicted in absentia for ordering a 2003 Bogota bombing that killed 36. Castellanos was allegedly involved in drug trafficking and well-known kidnappings.

The other commanders’ noms de guerre are Ivan Ali, Albeiro Cordoba, Enrique Marulanda and El Zarco Aldinever, the source said.

The head of the JEP said Martinez informed her of the investigation by phone on Friday morning and assured her none of the investigated officials are magistrates.

“We express our complete disposition for this case to be clarified quickly and made known to the public, which should have the utmost certainty in our commitment and dedication to the fulfillment of our duties,” Patricia Linares said in a statement posted on the tribunal’s Twitter account.

President Ivan Duque, who was elected on a promise to modify the FARC deal, told reporters Martinez should proceed with the investigation.

Most of the more than 6,000 former FARC fighters who demobilized last year were given amnesty and financial help, but many commanders are expected to appear before the tribunal.