The incident caused panic at the airport, besides delaying a Manchester-bound PIA flight for a couple of hours, after the crew staged a sit-in against the detention of their colleagues.
The customs authorities had information that 11 of the 14 crew members of PK-758 flight, including the captain and a purser, brought over 20 iPhones-5S (worth over Rs 105,000 each) from London on Friday during its launch, Dawn reported.
"The accused are office-bearers of the PIA staff union (CBA) and they did it under a plan. They first managed to get their duties changed by requesting the actual crew members for the flight in connivance with the relevant admin staff," Dawn quoted a senior PIA official as saying.
He said the accused left for London to purchase iPhones at cheap rates to sell them in Pakistan at higher prices.
He said some of their rivals in the union informed the customs officials about the plan before their return.
"As soon as the crew members reported in the lounge after landing of the plane, the authorities searched them. But they did not find iPhones. Later, they learnt that the accused had handed over the phones to a passenger," the official said.
The phones were later recovered from the passenger.
The authorities also reportedly recovered 5,000 British pounds from the captain and some other crew.
The official said then the accused called their fellow crew members who were about to depart for Manchester.
The crew members, along with some other union staff, staged a sit-in and chanted slogans against the authorities for harassing them.
The protests ended after the detained crew members were released.
A PIA spokesman said an inquiry had been launched.
"Since it is a serious matter, an inquiry is under way. We will be able to tell who is responsible for the incident after the inquiry," the spokesman said.