The ED officials picked up Sarnaik's son from his residence and reached the probe agency's office at Ballard Estate in south Mumbai around 3.15 pm, an official said.
They said the searches are being conducted by the central agency at 10 locations linked to Sarnaik in Thane and Mumbai under the Prevention of Money Laundering Act (PMLA).
The agency, officials sources said, will initiate a fresh round of questioning of the suspects.
They said the central probe agency has filed the enforcement case information report (ECIR) that is equivalent to a police FIR.
The ED has recently filed a charge sheet against Kochhar, Deepak Kochhar and Videocon Group promoter Venugopal Dhoot on money laundering charges.
The court will consider his bail plea on Monday. A senior Supreme Court lawyer is likely to argue for Sivasankar.
Many TMC leaders will spend rest of their lives in jail after ED traces their illegal assets: Dilip Ghosh
While addressing a programme here, Ghosh said, many leaders of the ruling TMC in the state have made a lot of "illegal" money and "no one will be spared".
The IAS officer also claimed that he was an easy political target because of the post he held.
His tenure was to end next week as the ED director's post comes with a fixed term of two years.
The team had interrogated Swapna at Attakulangara women’s jail in Thiruvananthapuram to seek clarity on the iPhones which were gifted to five persons including Sivasankar as a bribe.
While ED claims Sivasankar was the mastermind behind gold smuggling and money from Swapna’s locker was of the bureaucrat contradict the probe findings of the other two agencies.
Driver Ani Kuttan, Arun S had carried out financial transactions with Kodiyeri’s son
There have been fund transfers to a few people associated with political parties in the state and the agencies are collecting more details about it.
The ED requested the court to extend his custody for one more day as several new pieces of information were received after interrogating Swapna Suresh at the jail
Enforcement Directorate officials of Kozhikode unit questioned K M Shaji, MLA, in connection with the Azhikode Plus II bribery case, on Tuesday.