According to the police, the suspect has unsuccessfully sought asylum in Sri Lanka by claiming death threats from an Indian NGO.
The CID was also permitted to refer him to a doctor to obtain a report on his physical and mental condition.
He was arrested on a complaint by Namal Kumara of the Anti-Corruption Force, who claimed on September that a DIG was planning to kill president Sirisena and former defence secretary Gotabhaya Rajapaksa.
However, police media spokesman Ruwan Gunasekara told journalists on September 26 that contrary to media reports, the Indian man had not revealed any detail about a murder conspiracy.
What he has said is that he had come to believe the existence of a conspiracy, after reading newspapers and watching television in Sri Lanka.
Meanwhile, media minister Mangala Samaraweera accuses certain media of misleading the country by reporting untruths about a murder conspiracy.
The CID has not made any oral or written submission to the court to that effect, he says in a statement.
A resident of Kerala state, the suspect identified as M. Thomas had come to Sri Lanka in March 2017, and despite the expiration of his visa, he had gone to stay in a room at Thewatte in Ragama.
He is unemployed.
The Indian high commission in Colombo says investigations so far have revealed that the suspect has a history of an unstable mind since 2000.
Police are investigating as to what he had done in Sri Lanka and his income avenues.