Prosecutors are not sure what Doli Sharief Pulungan planned to do with the scopes, Assistant US Attorney Meredith Duchemin said.

Pulungan offered investigators various explanations, Mr Duchemin said. He said he wanted the scopes to hunt boars, then said he needed them for a rifle competition in Indonesia, then said it was all a misunderstanding and a joke. Text messages investigators recovered indicate coconspirators in Indonesia planned to sell the scopes to police.

There's no indication Pulungan has terrorist ties, Mr Duchemin said, 'but we really don't know what he was going to do with the scopes once he got them back to Indonesia. He provided a lot of explanations which, frankly, don't make a lot of sense.'

Mr Duchemin said Pulungan wanted to export 100 Leupold Mark 4 CQ/T infrared scopes. They're designed to attach to M-16 and AR-15 assault rifles.

The US State Department has classified the scopes as defense articles. That means they cannot be exported without a license from the Directorate of Defence Trade Controls, a State Department subdivision.

Pulungan in July approached someone he knew at an airport equipment company with whom he had been lining up other, legal exports to Indonesia, Mr Duchemin said.

Pulungan asked his associate to purchase the scopes from the manufacturer and ship them to his address for later shipment to Indonesia. The associate refused to help him.

Pulungan, who was traveling with two Indonesian passports listing different birth dates, offered another Wisconsin associate US$100,000 (S$137,000) in September to purchase the scopes and ship them to Saudi Arabia, the prosecutor said. Pulungan hoped a contact at a Saudi airline could ship the scopes to Indonesia, Mr Duchemin said.

But the associate contacted the FBI instead. The jury convicted Pulungan of conspiring to violate the Arms Export Act late on Tuesday after a two-day trial.

Pulungan's attorney, Mr Christopher Kelly, did not return a message left at his office late Tuesday afternoon.

Pulungan is scheduled to be sentenced on July 28. Indonesian authorities are still searching for his coconspirators.

Mr Duchemin declined to identify Pulungan's associates in Wisconsin or the equipment company, saying they did nothing wrong in the case. -- AP