Prosecutors in Peru say an army lieutenant arrested for allegedly letting small planes ferry cocaine unhindered out of the world's No. 1 coca-producing valley was getting bribes of $10,000 per planeload.

Authorities say Lt. Wilmer Delgado is the first Peruvian military officer arrested on drug charges in at least a decade.

Organized crime prosecutor Irene Mercado said Friday that legally authorized wiretaps indicate Delgado shared the bribes he collected with superiors.

She did not rule out additional arrests.

Delgado's arrest follows last week's Associated Press report that found Peru's armed forces 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.