Chanda Kochhar will soon depose before the agency as she has recently sought more time from the agency owing to some health issues and personal commitments, they said.
It is understood that she was supposed to depose before the ED on Thursday but skipped the appearance.
The agency is also preparing to analyse the details of assets of the Kochhars and others so that they can be provisionally attached under the Prevention of Money Laundering Act (PMLA).
Chanda Kochhar's brother-in-law and Deepak's brother, Rajiv Kochhar, has also been grilled by the ED multiple times in the case.
He is the founder of Singapore-based Avista Advisory and was also questioned by the CBI about his company's role in the restructuring of the loan.
Rajiv Kochhar was asked by CBI sleuths about the help he had extended to Videocon in relation to the loan from ICICI Bank, which was part of a Rs 400-billion credit given by a consortium of 20 banks to the group of Venugopal Dhoot.
The Kochhar couple have been questioned in the past too at the ED zonal office in Mumbai after the central agency conducted raids in this case on March 1.
The searches were conducted at the premises of Chanda Kochhar, her family and Venugopal Dhoot of Videocon Group in Maharashtra's Mumbai and Aurangabad.
The ED has registered a criminal case under the PMLA early this year against Chanda Kochhar, Deepak Kochhar, Dhoot and others to probe alleged irregularities and corrupt practices in sanctioning Rs 1,875-crore loans by ICICI Bank to the corporate group.
This action of the agency was based on an FIR registered by the CBI.
The CBI has named all the three and Dhoot's companies -- Videocon International Electronics Ltd (VIEL) and Videocon Industries Limited (VIL) -- in its case.
The anti-corruption probe agency also named Supreme Energy, a company founded by Dhoot, and NuPower Renewables, a company controlled by Deepak Kochhar, in the FIR.
It has slapped sections of the Indian Penal Code related to criminal conspiracy, cheating and provisions of the Prevention of Corruption Act on all the accused.
The CBI alleged that Dhoot had invested in Nupower through his firm Supreme Energy in a quid pro quo to loans cleared by ICICI Bank after Chanda Kochhar took over as the CEO of the bank on May 1, 2009.
The ownership of Nupower and Supreme Energy changed hands through a complex web of shared transactions between Deepak Kochhar and Dhoot, the CBI alleged.
During its preliminary enquiry, the CBI found that six loans worth Rs 1,875 crore were sanctioned to the Videocon Group and companies associated with it between June, 2009 and October, 2011 in alleged violation of laid-down policies of ICICI Bank, which have now become part of the probe.
The loans were declared non-performing assets in 2012, causing a loss of Rs 1,730 crore to the bank, it alleged.
The ED, the sources said, is also probing at least two other instances of loans given by ICICI Bank (during Chanda Kochhar's tenure) to Gujarat-based pharmaceutical firm Sterling Biotech and to Bhushan Steel group.
The agency is investigating these two instances of alleged bank loan fraud under the PMLA.