Peruvian police arrested an army lieutenant Thursday, alleging he regularly collected bribes from drug traffickers for letting small planes ferry cocaine out of the world's No. 1 coca-producing valley.

The arrest was Peru's first of a military officer on drug trafficking charges in at least a decade, said Jorge Chavez Cotrina, Peru's chief organized crime prosecutor.

It came a week after an Associated Press report that said the Peruvian armed forces have turned a blind eye to the daily airborne ferrying to Bolivia of more than a ton of cocaine from Peru's Apurimac, Ene and Mantaro river valley, called the VRAEM. Peru's military has controlled the Ireland-sized region for nine years.

Lt. Wilmer Eduardo Delgado Ruiz was arrested in the nearby city of Satipo after being summoned from his base in the jungle valley, Chavez said.

"The information that I have is that he was charging a sum of money for every flight that left the VRAEM," said Chavez.

He said he did not yet know how much Delgado was collecting per flight and said it was too early to say if other arrests were expected.

Police say four or five flights a day haul more than 300 kilos each of semi-refined cocaine from the valley. An accused narco pilot told the AP that local military commanders charge $10,000 per flight. The pilot also said no plane arrives with less than a half million dollars to pay for the cocaine and bribes.

A senior narcotics police official told the AP that Delgado, who faces 35 years in prison if convicted of aggravated drug trafficking, had been under investigation since early 2015.

The official said the probe was based in Lima, backed by U.S. Drug Enforcement Administration agents and included the examination of Delgado's bank accounts. He agreed to discuss the case only if not quoted by name because he was not supposed to give out information on a continuing investigation.

"We still have people out in the field," said the official, who was asked about Delgado's seniority at Base 79, one of more than 30 in the valley, where the military has been battling drug-trafficking Shining Path rebel remnants who now number about 60. "He's just another officer there. There are also captains and majors."

Prior to AP's report last week, prosecutors and police said that not a single military officer was under investigation for drug trafficking.

Afterward, Defense Minister Jakke Valikivi announced that his ministry and the military command would open a joint investigation.

Valikivi also called the AP report "tendentious" and drug czar Alberto Otarola said in a newspaper interview that it "offended the image of Peru."

Peru surpassed Colombia in 2012 as the world's No. 1 cocaine-producing nation.