He is accused of attempting to bribe an Election Commission official for retaining the party's poll symbol of 'two-leaves' for his faction.
The Delhi Police personnel, who were inside Dinakaran's house for about 20 minutes, declined to speak to the waiting media while leaving the premises.
State Finance Minister D Jayakumar said such "politics of opportunism" will not succeed.
The Enforcement Directorate has registered a money laundering case against All India Anna Dravida Munnetra Kazhagam-Amma leader TTV Dinakaran and others in connection with the Election Commission bribery case.
Special Judge Poonam Chaudhry sent Dinakaran and his aide Mallikarjuna to Tihar Jail till May 15 after the police said that the accused were not needed for custodial interrogation.
The police sought two-day custody of alleged hawala operator Nathu Singh, who was arrested on Friday night.
His call logs, WhatsApp messages and SMSes are also being examined, police said.
Vijayakanth was unwell for quite some time and his wife Premalatha took over the reins of the party days ago.
Roopa had alleged that Rs 2 crore had exchanged hands to provide special facilities to Sasikala.
The AIADMK leader, however, told cops he believed that the arrested middleman -- Sukesh Chandrasekhar -- was a high court judge.
Dharmapuri district Child Welfare Officer J Raja Meenakshi has filed a complaint with the Chennai city police alleging that the minister demanded Rs 20 lakh to transfer her to Chennai.
Mallikarjuna, a long time friend of Dinakaran who was also arrested, has also been remanded to police custody for five days.
Siddaramaiah said she could have approached any of her superiors about her charges against senior officials.
The IT sleuths recovered 'incriminating' documents from the premises of Vijayabaskar and others, officials said.
The meeting also discussed the validity of the appointments made by Sasikala before going to jail.
Deepa's brother Deepak was present in the house when she arrived.
Roopa has now been posted as commissioner for road safety & traffic.
Police claimed that money recovered from alleged middleman Sukesh Chandrashekar was sent by Dinakaran.
The court granted the relief to the two saying they were no longer required for custodial interrogation and have been asked to furnish a personal bond of Rs five lakh each and two sureties of the like amount.
DG (Prisons) rejected allegations, saying action will be taken against DIG D Roopa.
The Rs 89 crore question before Tamil Nadu now is what shape a central intervention would take, and if there would be any role whatsoever for acting governor, Ch Vidyasagar Rao, in it, says N Sathiya Moorthy.