Early July, footage had emerged of Mr Pal addressing meetings of party workers and saying that if any of his workers were attacked, he would "set his boys" on women relatives of CPM workers and get them raped.
He had also said he owned a gun and would not hesitate to shoot dead CPM workers.
The rape-murder comments created outrage across the country but Chief Minister Mamata Banerjee had let him off after he sent the Trinamool leader a letter of apology.
A PIL was filed in the high court. A single bench judge, Justice Dipankar Dutta, had ruled that an FIR be filed against Mr Pal within 72 hours and that CID probe the speech.
However, within days, the state government and Mr Pal appealed against the order in a division bench. After extensive hearing, the bench delivered a split verdict. Justice Girish Gupta struck down the single bench order, while Justice T Chakraborty upheld it. The case was then sent to Justice Nishita Mahtre.
Justice Nishita Mahtre today upheld, almost entirely, the order of the single bench judge Justice Dutta in the case. The only element Justice Mahtre left out is court monitoring of the investigation.
The Opposition is viewing today's order as a blow against the Mamata Banerjee government.
Knowing the Mamata Banerjee government, if the court does not monitor the investigations, the government will hijack it and nothing will come out of the FIR.