Additional Director General of Police (anti-Naxal operations) Ram Nivas told PTI that the police has got some important clues but refused to elaborate due to security reasons.
He said the police has quizzed the officials who had taken part in Gram Suraj Abhiyan program at Majhipara village, during which 32-year-old Menon was abducted yesterday.
According to the officials who were present, some 50 ultras, including women, approached the spot where the program was underway, and took away Menon after shooting two of his guards dead.
Around 20 of them were armed, the officials told police.They first shot guard Kishun Kujur. Another guard, Amjad Khan, returned the fire, in which one of the Naxals was reportedly killed, while Khan too died in the exchange of fire.
According to Ram Nivas, police suspect this to be the operation of Military' dalam of the Naxals, and most of those took part in the operation were from Chhattisgarh.
Naxals had not made any demand in return for the release of the Collector so far, Ram Nivas said.
He also said that 32-year-old Menon suffered from asthma, and was not carrying his medicines when he was abducted.
Meanwhile, Chief Minister Raman Singh said that state would try its best to rescue Menon.
Asha Menon, the abducted officer's wife, has appealed to Naxals to release her husband on humanitarian grounds, saying he was sick, and does not have necessary medicines with him.
A special police team has been constituted for rescue efforts.Menon's family said the officer was aware of the threat of possible kidnap of officials in the region but that never deterred him from responding to the call of duty.
"We heard that there were warnings about possible kidnap of senior officials in that region. He was advised not to go out without security. He was very careful. But he had to attend to his duties," Menon's father-in-law Venugopal said.