Six of the arrested persons were owners of small-scale units that manufactured the components of the rocket launchers, while one was the agent of Kranthi Transport, a company in Chennai that was used to send the components to Andhra Pradesh, Tamil Nadu's Director General of Police D Mukherjee told reporters.

"An investigation by the 'Q' branch has revealed that the brain behind this matter is Raghu alias Srinivasa Reddy, who booked the consignment to be delivered to Vijayawada," Mukherjee said. "We are in possession of certain photographs which reveal that Raghu (30) and his wife Sudharani (25), who were staying in a rented house at suburban Ambattur, have links with Naxal groups in Andhra Pradesh," he said.

In the early hours of Friday, police raided Raghu's house and retrieved several components and an album with photographs of Raghu and Sudharani in a Maoist camp, he said. Police also seized over 20 rocket launcher spare parts, during raids in the workshops, including one owned by Raghu.

However, where these parts were assembled into the complete launchers is yet to be ascertained. Following indications that Raghu and Sudharani could have fled to Nellore in Andhra Pradesh, a special team was sent there to nab them.

Denying that an intelligence failure on the part of Tamil Nadu Police had resulted in the manufacturing of the rocket launchers in the state, Mukherjee said this had been going on on a very small scale and in a segmented manner for the past three years.

"Raghu, who was staying in a rented house in Ambattur, won the confidence of owners of small units nearby and provided them with sketches for the spare parts and funded them," he said.

Asked whether the manufacturers were aware of the ramifications, he said, "Only an investigation will reveal whether they had any criminal intentions." The rocket launchers supplied over the past three years to Naxalites in Andhra Pradesh have been used in attempts to attack police stations and important areas there, Q Branch Superintendent of Police Davidson Devaasirvadham said.

"Approximately 700 to 1,000 launchers could have been delivered to the Naxals in the past three years, all of which were manufactured in Ambattur," he said.

The Q Branch will continue to raid other units in the industrial estate to ascertain the involvement of others in the operation, he said. Police on September eight raided at least 6 godowns of a private transport company here and sealed one of them, from which the consignment of arms seized by Andhra Pradesh Police was suspected to have been booked.

Andhra Pradesh Police seized 875 rocket launchers and other ammunition from different places in Mahabubnagar and Prakasam districts believed to be sent to Maoists.

After the seizures, they raided the offices and godowns of Kranthi Transport Company in Chennai, which is believed to have been used to smuggle the weapons.