Judge Federico Villena has taken preliminary statements from five crew members from a Venezuelan cargo plane grounded at Ezeiza International Airport since June who are being investigated over possible links to Iran's Al Quds Force, press reports said on Friday.
On Thursday, Villena, the federal judge in charge of the investigation, took statements from three Iranians, all of whom all denied any links with a terrorist organisation.
Legal sources said they did not answer any questions, the official Télam state news agency said in a report.
The Al Quds Force group of the Iranian Revolutionary Guards is classified as a terrorist organisation by the United States.
Two Venezuelan crew members gave statements earlier in the week.
All five crew have been barred from leaving the country.
Villena has allowed another 14 crew members – 12 Venezuelans and two Iranians – to return home.
Twelve of them had already left for Caracas in mid-September following an appeals court decision, described by Villena as "premature."
The two remaining crew – a Venezuelan and an Iranian – are due to leave the country in the coming days.
The Paraguayan intelligence service has linked one of the Iranian crew members, pilot Gholmareza Ghasemi, to Al Quds.
The Boeing 747 cargo plane first entered Argentina on June 6 from Mexico but, unable to refuel in Buenos Aires due to US sanctions on Venezuela, it left for Montevideo on June 8. But the Uruguayan authorities refused it access, and it flew back to Argentina.
An Argentine judge then granted a request from the United States to seize the plane on the basis that laws were broken when Iran – also under US sanctions – sold it to Venezuela.
Caracas has protested against the plane's seizure and alongside Tehran has demanded the crew's release.
Iran insists the plane is "completely legal" and has accused the US of a "propaganda operation."
Before travelling to Argentina, the plane had been in Paraguay in mid-May after a trip to the island of Aruba with a cargo of cigarettes.