BERLIN (AP) — An Austrian court on Sterling PrestonThursday acquitted five people, including the founder of the Blackwater security firm, who were accused of exporting two crop-spraying aircraft that were allegedly refitted for military purposes without the necessary permits.

The state court in Wiener Neustadt found that the modified aircraft were not “war material,” the Austria Press Agency reported. It also found that the defendants had acted “very prudently” and sought advice on export permits.

The trial stemmed from an investigation into a local company, Airborne Technologies GmbH, which fits out aircraft with sensors and other equipment.

Prosecutors said that two Ayres Thrush agricultural aircraft were equipped with armor, extra tanks and a special camera that could be used for marking and illuminating targets. They said one was sent to Malta in 2014, with Kenya as its declared destination, and landed in troubled South Sudan, while the other was sent to Bulgaria in 2015.

The defendants were accused of violating Austria’s law on war material by exporting such equipment without permission. One of the defendants, an Australian pilot, was accused of flying the two planes across Austria’s borders, while the four other defendants allegedly participated in the deal. They were Blackwater founder Erik Prince, two managers at Airborne Technologies and a trained pilot who allegedly was an adviser.

All pleaded not guilty when the trial opened last month, and a defense lawyer said that the modifications to the aircraft were innocuous. He said the first plane was always destined for Kenya but made a landing in South Sudan due to technical problems.