The materials seized included pipe bombs, raw materials for land mines, hand grenades, electronic detonators, explosives, utensils and groceries, DIG S.S. Krishnamurthy told reporters at Kodaikanal on Monday.
The seizure came two days after a Maoist rebel was killed in an encounter in the area.
Krishnamurthy said an intense search was on to nab the Maoists who had escaped from the police dragnet and neighbouring states also have been alerted.
This is the first time after 1970 that Tamil Nadu Police has launched a major operation to crack down on Naxal activities.
In 1970, the special police force, headed by former state police chief Walter Dewaram had curtailed their activities in Krishnagiri and Dharmapuri districts, considered Naxal strongholds during that time.
The Special Task force, which was formed recently after reports of resurgence of Naxal activities in remote areas, killed a Maoist identified as Naveen Prasanth and took two others into custody.
Police said investigations revealed that a Theni-based woman doctor and Communist party members based in that town were also helping the Maoists.
Hospitals in Theni, Dindigul and border areas were being closely monitored and checkposts set up. There was also a plan to deploy more intelligence wing personnel in hilly villages and in the coastal belt to curb the Maoists activities and to prevent arms training in remote areas.
DIG (Intelligence) Shankar Jiwal is camping in the area to monitor the overall operations.
Police officials said the Maoists have sympathisers in Theni and Dindigul districts and steps should be taken to cut off their supply lines.
A report from Dharmapuri, meanwhile, said that the body of Maoist Naveen Prasanth, who was killed in the encounter, was buried at his native village Mookanur.
Meanwhile, a retired official of the Intelligence Bureau has suggested that a team of intelligence officials be posted in border districts, which are strategic points for the Naxals.
"If they keep moving from one district to the other or from Tamil Nadu to Kerala and back, then it would turn out to be a wild goose chase," he said.
There should be coordination with police forces of neighbouring states, which was lacking at present, he added.