Mumbai: The CBI on Saturday evening arrested the suspected shooter in the murder of rationalist Narendra Dabholkar, two days before the fifth anniversary of the rationalist's death.

CBI sources said Sachin Prakasrao Andure is suspected to be the man who shot Dabholkar on August 20, 2013, while he was taking a morning walk near the Omkareshwar temple in Pune.

Andure was arrested from Aurangabad by a joint team of the central agency and the Maharashtra anti-terrorist squad (ATS).

Dabholkar's son Hameed told PTI: "This is the second arrest in five years in the case and we hope that with this arrest, investigating agencies will get to the real perpetrators...."

Sources in the ATS said that one of three people arrested earlier this month in the Nala Sopara terror case had admitted to being involved in the murder of Dabholkar and named Andure during interrogation.

"Both had used a motorcycle for the murder of Dabholkar," a source said. "We informed the CBI and Andure was brought in for interrogation after which he was arrested."

The Nala Sopara case is about an alleged plot to carry out terrorist attacks in Mumbai, Pune, Nala Sopara and Satara in Maharashtra that was busted this month.

The ATS had arrested Vaibhav Raut, Sudhanva Gondhalekar and Sharad Kalaskar from Nala Sopara in Palghar and from Pune along with arms and explosives. The three were produced before a Mumbai court on Saturday and remanded in ATS custody till August 28.

According to sources, Andure had for the past 14 months been staying at a rented house in Aurangabad's Rajbazar area with his wife and daughter. He had secured a job at a textile store in Nirala Bazar.

Investigators have been trying to find links between the murder of journalist Gauri Lankesh in Bangalore last year and those of rationalists Dabholkar, Govind Pansare and M.M. Kalburgi in Maharashtra and Karnataka between 2013 and 2015.

The arrest of Amol Kale, a Maharashtra resident suspected to be the main conspirator behind Gauri's murder, had led the investigators to Raut, whose name was found in a diary seized from Kale.

"Raut's arrest made possible this big breakthrough in the Dabholkar murder case. We expect the other conspirators to be arrested soon," an officer said.

"Andure's arrest strengthens the possibility that members of the same outfit, or an umbrella body of similar outfits, carried out all the four murders."

The CBI and Maharashtra's CID, both probing Dabholkar's murder, had faced Bombay High Court's anger for failing to make headway in the case.

A radical Hindu organisation, the Sanatan Sanstha, has been under the scanner in connection with the murder. The CBI had earlier arrested Virendra Tawde, a doctor and a member of Sanstha affiliate Hindu Janajagruti Samiti, as a conspirator in the case. He is currently out on bail.

After the arrests in the Nala Sopara case, a spokesperson for the Samiti had described Raut, 40, as a "daring cow protector".

Sources in the ATS said the Dabholkar and Pansare families' security had been intensified following a tip-off from their Karnataka counterparts about a possible threat to their lives.