New Delhi

The doctors arrested in connection with the "white-collar terror module" had raised more than Rs 26 lakh to procure materials used in the deadly blast near Red Fort, an official said on Thursday.

The four suspects -- including ”Dr Muzammil Ganaie, Dr Adeel Ahmad Rather, Dr Shaheen Sayeed and Dr Umar Nabi -- had pooled in the amount in cash, which was handed over to Dr Umar for safekeeping and operational use, they said.

Dr Umar -- who hailed from Jammu and Kashmir's Pulwama and was an assistant professor at Al Falah University in Haryana's Faridabad -- was behind the wheels of the Hyundai i20 that exploded in the busy Red Fort area on Monday evening.

Investigators believe the fund was linked to a larger terror conspiracy.

Using the pooled money, the group had allegedly purchased around 26 quintals of NPK fertiliser approximately worth Rs 3 lakh from suppliers in Gurugram, Nuh and nearby towns.

The fertiliser, mixed with other chemicals, is commonly used to manufacture Improvised Explosive Devices (IED), officials said.

Police sources said the group's procurement of such a large quantity of the fertiliser ”has become a key lead in the ongoing investigation. The financial transactions and delivery records are being verified, they said.

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Sources also said that Umar and Muzammil had a disagreement over the handling of funds in the days leading up to the explosion. The investigators are looking into whether this dispute affected the group's plans or the timing of the attack.