According to the ED officials, Patel arrived at the ED office in Mumbai here in the morning and was being questioned under the sections of Prevention of Money Laundering (PMLA).
The probe agency officials said he is being questioned about the 15-storey Ceejay House developed by Milenium Developers and two floors given to the family members of Mirchi.
The official also said that Patel will be asked about his relations with Mirchi's first wife Hajra Memon, who was the beneficiary of the two floors in the Ceejay House here.
The NCP leader though claimed that she got these through M.K. Mohammad who earlier owned restaurants on the property that was knotted in legal disputes.
Patel has denied any wrongdoing or any links with Mirchi or his associates.
The ED official also said that the agency will also ask Patel about over a dozen of shell companies identified during questioning of several people linked with the Mirchi family.
The probe agency earlier this week had questioned Mirchi's brother-in-law Mukhtar Memon, who controls most of the properties in India.
On October 12, the ED also questioned two aides of Mirchi on their links with politic and builders, who were allegedly involved in transaction of prime properties reportedly belonging to Dawood Ibrahim's D-company.
The accused, who are from Mumbai, have been identified as Haroun Yusuf and Ranjeet Singh Bindra. Bindra acted as a broker for the land deal while Yusuf transferred the money to a trust and facilitated the deal.
The agency found that Yusuf became a British national in 2004 and played a crucial role in illegal land deals between Mirchi and developers that were carried out by Bindra for brokerage of around Rs 30 crore.
According to the ED, the purchase of the three assets by late Mirchi, who died in London in 2013, were allegedly made from the proceeds of the crime.
The three buildings Sea View, Marium Lodge and Rabia Mansion were sold to a firm for Rs 225 crore in 2010, out of which Mirchi allegedly received the majority share.
The agency would question Patel on dealings as the agency has identified several bank accounts through which the laundered money were routed to London.
( With inputs from IANS )