Officials said the central probe agency has registered a criminal case under the Prevention of Money Laundering Act after taking cognisance of a Delhi police FIR in the matter.
They said the agency will probe the possible "proceeds of crime" as part of its charter under the anti-money laundering law and soon will issue summonses to the accused.
A meeting of the ED and Delhi police officials has taken place recently and it is expected that after the central probe agency registered a separate case, a few more such meetings could be held to take the probe forward.
Dinakaran and his aide Mallikarjuna were sent to the Tihar Jail till May 15 by a Delhi court on Monday after the police said that the accused were not needed for custodial interrogation.
Dinakaran was arrested on April 25 after four days of questioning by the Delhi police for allegedly attempting to bribe an unidentified EC official to get the undivided AIADMK's 'two leaves' election symbol for his faction for a byelection to the R K Nagar assembly seat in Tamil Nadu which was later cancelled by the Election Commission.
Middleman Sukesh Chandrasekar, who was the first to be arrested in the case, had struck a deal for Rs 50 crore to help the faction keep the 'two leaves' symbol.
The EC had frozen AIADMK's 'two leaves' symbol after two factions led by Sasikala and former chief minister O Panneerselvam staked claim to it.
The AIADMK-Amma faction leader has been accused of allegedly arranging the amount from undisclosed sources and getting it transferred from Chennai to Delhi through illegal channels.
The court had on April 26 remanded the duo to five-day custody of Delhi Police which said it needed to unearth the money trail and the entire conspiracy in the case.
Mallikarjuna, who had been accompanying Dinakaran everywhere ever since the arrest of alleged middleman Sukesh Chandrasekar on April 16, was arrested for facilitating the alleged Rs 50-crore deal between Dinakaran and Chandrasekar.
Chandrasekar is in judicial custody till May 12.
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