The investigators have received some eye-opening leads from the five suspects who were remanded for four days by the Dhaka's Chief Metropolitan Magistrates Court on Wednesday.
However, detective police are yet to identify the masterminds involved in gold smuggling.
Police hints at revealing leads provided by the suspected gold smuggling key leaders after they were quizzed by the detectives with the help of other security agencies.
Investigators are hopeful that they would be able to crack the mafia network engaged in gold and currency smuggling for years. A deputy general manager of Biman and four others are being questioned for four days in police custody over their suspected ties to gold smuggling.
A senior police official told The Daily Observer days before arrests of the suspects Biman DGM Emdad Hossain, Flight Captain Shahidullah, Schedule in-charge Tozzamel Haque, Uttara's Farhan Money Exchange owner Harun-ur-Rashid and Biman contractor Mahmudul Haque Palash that they received green signal to go ahead of the investigation without fear and influence.
Foreign exchange trader Harun was book keeping of finances and Biman flight captains along with cabin crews were deployed in chosen flights for the gold smuglling and ensured that the gold bars passed through airport customs without trouble.
Palash, believed to be the coordinator of the smuggling operations is a spouse of a Biman cabin crew and he lost his job after his first wife exposed him for possessing forged educational certificates which caused him to lose his job as pilot with GMG.
Influential Palash claimed to be "adopted son" of Biman Chairman Jamal Uddin Ahmed and also friend of chairman's son Zobaer Ahmed, who recently quit job as a pilot of Regent Airways.
Air Marshal (Retd) Jamal Uddin Ahmed, however dismissed the claim of Palash and said he has no relation with Palash nor he is friend of his pilot son. Both Palash and Jamal Uddin hails from Comilla.
Police has also implied that they are likely to quiz the most influential co-pilot Shamim Nazrul also Deputy Chief Training who is presently on unauthorised leave to Canada.
Shamim was personal staff of Chief of Air Staff Jamal Uddin before he retired. Later he (Shamim) was recruited in Biman without any bureaucratic hassle. Soon after he acquired commercial pilot licence (CPL) from Bangladesh Flying Club he joined the cabin crew and very quickly rose to Deputy Chief Training under the blessing of Jamal Uddin.
Police have discovered that Palash, Zobaer and Shamim are business partners in procuring business deals from Biman. The business deals were exclusively handled by Palash with tacit support of Jamal Uddin, who did not deny for offering favours.
Police has unofficially visited the posh home of Zobaer at New DOHS, which baffled the investigators. They (police) asked how a pilot can afford to own a posh residence with modest wages and benefits.
The detectives who have extended their branches of investigation suspect that the money was from kickbacks from the two Boeing 777 ER Series 200 on wet lease from Egypt by Biman for Hajj flight. Unfortunately the two aircrafts on wet lease with a dozen foreigner crew has not been returned for mysterious reasons, the source said.
Biman chairman's son Zobaer despite his piloting experience qualification does not comply to Biman's requirement for medium haul aircrafts, he was given an offer letter to join Biman cockpit crew, a highly placed official source said.
His recruitment is caught in the mud after several cadet pilots of Biman filed a case and acquired an injunction of him (Zobaer) and other handpicked pilots by Shamim.