Dismissing the petition, Justice S Satishchandran said the speech and the revelations prima facie discloses commission of cognisable offence, which fully justifies registration of crime and said the investigation could go on.
"Right to dissent guaranteed in the Republic governed by democracy is met with a brutal force, and the dissenter is annihilated, whether it be as a retaliatory measure on the attacks made on one's party men or group and if it is not checked, then it will sound the death knell of democracy," he said.
"Shocking revelations by Mani in his speech that brutal murders of some political activists opposed to his party while he was district secretary, was part of a sinister diabolical plan after a list was prepared by him to annihilate political opponents," the court said.
Mani, who was Idukki district secretary of the Communist Party of India-Marxist, had at a public meeting stated that the Marxist party had eliminated at least three of its political foes in the 1980s. A deeply embarrassed CPI-M had later removed him from the post.
The police had registered cases against Mani and five others on the basis of the disclosures, including one pertaining to the murder of a Congress worker who was shot dead on Nov 13, 1982.
Mani had contended the judicial first class magistrate, Nedumkandam, had no jurisdiction to order a further probe.
When trial was concluded, the accused were acquitted and hence the judgment of acquittal becomes final, he had submitted. He had contended that the FIR in the case was prepared in Thiruvananthapuram at the instance of the chief minister and home minister and was handed over to Idukki superintendent of police with a direction to register a crime.
There is no material available warranting registration of three new crimes, he stated. Due to "continuous intervention" of the chief minister and the home minister, the police was registering new crimes in a "clandestine manner", fabricating evidence and procuring witnesses inimical to the petitioner, he had alleged.
Mani contended registration of a crime was part of a state level conspiracy hatched by the Congress and the home minister who controls the Special Investigation Team, to destroy him and the CPI-M.
"No political party or leader can claim to be the law unto himself and he is above the law, then the rule of law, and that alone has to prevail," Justice Balakrishnan said in his 72-page judgment.
Pointing out that Mani was a leader of a national party, the court said the right to engage in political expression and association is enshrined in the Constitution.
Any interference with freedom of a party or its party men by an individual or any other party or state, that too by resorting to violence, negating the rule of law, was "interference with the freedom of political expression and association guaranteed by the constitution," the court held.
"It is implicit that the right to life and liberty should be free from fear and threat to life as the life under fear and threat to death will be no life at all. Right to life is something more than survival of animal existence and it will include the right to live in peace with human dignity," the court said.
Mani's controversial disclosures that CPI-M had eliminated its political foes in Idukki in the 1980s had deeply embarrassed the party, which was on the defensive as some of its functionaries had been arrested in the murder of Marxist rebel and RMP leader, T P Chandrasekharan on May 4.