A local court Thursday granted custody of lawyer Sanjeev Punalekar to the CBI till June 23 after the agency said there was a possibility of Goa headquarters of right-wing outfit Sanatan Sanstha having a connection with the murder of anti-superstition activist Narendra Dabholkar.
The central agency also said it was trying to ascertain the identity of one ''Sadguru'' mentioned in a letter written by Punalekar.
Special CBI judge RM Pande granted Punalekar's custody to the investigation agency.
Punalekar, who had represented some of the other accused in the case, was in CBI custody after his arrest, but was later sent to judicial custody.
Special public prosecutor Prakash Suryawanshi said Punalekar needed to be questioned about documents and information recovered from his laptop.
"It includes an incriminating letter from Punalekar mentioning the court proceedings of Nalasopara explosives (seizure) case, passing some observations about the judge," he said.
"The same letter also mentions one ''Sadguru''. The CBI has to interrogate the accused as to who was the person, whom he was reporting to, who was his handler and to know the higher-level person in the organisation," Mr Suryawanshi said.
This "higher-level" person is based in Goa and the CBI may have to take Punalekar to some places, including the coastal state, to confront various persons, he said.
The CBI also found a letter dated September 17, 2012, written by Punalekar to Dabholkar, which indicated that the "accused was against Dabholkar even in 2012", he added.
Narendra Dabholkar was shot dead in Pune on August 20, 2013.
The prosecutor said the CBI had found a folder named "Dabholkar" on Punalekar''s laptop with several files.
A June 2016 email revealed that one of the accused, Dr Virendrasinh Tawde, had been directed by someone in Goa to leave everything and focus on the anti-superstition bill for which Narendra Dabholkar was campaigning, Mr Suryawanshi said.
The Maharashtra Prevention and Eradication of Human Sacrifice and Other Inhuman, Evil and Aghori Practices and Black Magic Act, which had faced opposition from right-wing organisations, was finally passed after Dabholkar's death.
"The headquarters of the Sanatan Sanstha is at Fonda (Ponda) in Goa and there is a likelihood of a connection with the headquarters in this murder case... Interrogation is required to know the co-conspirators," Mr Suryawanshi said.