MUMBAI (AFP) - Indian investigators seized more than 100 bags stuffed with cash, gold and diamond jewellery during a raid on four trucks in Mumbai, marking one of the city's largest such hauls, reports and officials said on Wednesday.

Income tax and anti-terror investigators raided the vehicles on Monday night at a south Mumbai train station after a tip-off and questioned 45 people accompanying the goods, Director General of Income Tax Swatantra Kumar told reporters.

"Cash amount is about 100 million rupees (S$2.13 million). Verification and valuation of jewellery is in progress. No further details," said Mr Kumar.

Income tax officials said they thought the cash and jewellery was bound for Gujarat state, north of Mumbai, as part of a "hawala" transaction, the Press Trust of India (PTI) news agency reported.

The term "hawala" describes an illegal Indian network used to transfer money without using the formal banking system. It is popular among ordinary consumers who use it to transfer small amounts, but is also a haven for criminals.

According to PTI the couriers travelled with police escorts, who explained that it was a regular practice for police to accompany private couriers carrying high value goods to prevent banditry.

Deputy commissioner of police Nisar Tamboli told the Mid Day newspaper: "For the last 15 years or so, an escort from a local police station is usually provided to these couriers as they carry big sums of cash and other valuables.

This is done to prevent robberies and dacoity. Murders have been committed over this." A senior police official told PTI that it is not the police's responsibility to verify whether the cash and jewellery were accounted for or not.

The cash and jewellery has not yet been accounted for, officials told PTI.