Mumbai, Jul 2 (IANS): A courier consignment of cash, gold and diamond jewellery, estimated to be worth a staggering Rs.200 crore (about $33 million) was seized here late Monday by the National Investigation Agency and Income Tax Department, an official said.

It is being billed as the biggest operation of its kind and the sources and destinations of the consignment are being probed.

Income Tax Director General Swatantra Kumar told mediapersons here Tuesday morning that the consignment, intercepted near the busy Mumbai Central terminus around 9.30 p.m. Monday, was bound from Mumbai to Ahmedabad and other destinations by the Gujarat Mail train.

It was brought in four trucks carrying around 150 bags chock-full with cash and jewellery, stumping the investigators who suspect a terror angle, a top IT official requesting anonymity said here Tuesday.

At least 47 people, including personal couriers, locally known as 'angadiyas', were detained and 20 were let off after initial questioning by the two agencies early Tuesday morning.

The operation was carried out following a tip-off received by the NIA at least a week ago.

NIA roped in the IT Department for help as a huge amount of cash was involved.

Not ruling out a terror funding angle, at least a dozen of those detained are being questioned separately by the NIA.

Counting of the cash and valuation of the jewellery is currently on at the IT headquarters in Mumbai and the true value of the consignment is expected to be known only within another day or so, the official said.

Swatantra Kumar, while declining to peg a value to the seizure, said that a team of officials is busy counting the seized cash and ascertaining the value of the jewellery which is expected to be known by Wednesday.

Replying to a query on whether a terror angle was suspected, Swatantra Kumar said that whatever is the outcome of the IT probe, it will be shared with NIA.

Mumbai's famous and trusted tribe of 'angadiyas', functioning since centuries, are known to transport huge amounts of cash and valuables like diamond or gold items, daily by trains from Mumbai to Gujarat and to parts of the country.