The searches by the Enforcement Directorate against three people linked to Robert Vadra continued on Saturday with official sources saying action is being undertaken by the agency on the basis of two first information reports filed by it.
They said the central probe agency is questioning at least four people on the second day of the raids.
Sources said the agency is recording the statements of these people, who have not been identified till now, under the Prevention of Money Laundering Act (PMLA).
The raids are being conducted as part of ED's money laundering FIRs, called ECIRs in the agency's parlance, in the Bikaner land scam case and one against absconding arms dealer Sanjay Bhandari, they said.
ECIR stands for Enforcement Case Information Report.
While Robert Vadra linked firm Skylight Hospitality and its officials have been grilled by the ED in the Bikaner land scam case, the agency has twice issued summons to Mr Vadra, the brother-in-law of Congress chief Rahul Gandhi, to appear in this case.
Police complaint was filed against controversial arms dealer Bhandari by the ED in 2016 based on an Income Tax Department and Delhi police complaint of his alleged indulgence in dubious defence deals.
Bhandari's case first came to light after the I-T department conducted searches against him in April, 2016 and recovered certain "sensitive" official defence documents from his premises.
As part of these raids, certain emails are also said to have been recovered that talk about renovation of a costly apartment in London in 2010 which was allegedly owned by Mr Vadra.
Mr Vadra's legal firm has denied that he owned the London property directly or indirectly. It has also denied Mr Vadra has any business ties with an arms consultant or his aides.
The tax department had shared a "seizure memo record" with the defence ministry to apprise it about the contents of these "sensitive" documents.
ED sources had said on Friday that "the searches are being carried out at the premises of two employees of firms linked to Vadra and another person". These people are suspected to have received commissions out of a defence deal and they subsequently invested these funds to acquire illegal assets abroad.
They, however, had not disclosed the names of the people whose premises were searched or the defence deal under their scanner stating that the "action was ongoing".
Mr Vadra's lawyer Suman Khaitan said ED officers "are inside his client's premises since 8/9 AM".
Suman Khaitan had alleged that the ED teams entered the premises of associates of his client without showing "search warrants".
He had claimed that the premises were locked from inside and questioned the government's motive behind it.
Suman Khaitan went on to claim that probably evidence was being fabricated.
The Congress reacted sharply to the ED action and said an "unnerved" Modi government was unleashing "vendetta" against Mr Vadra to divert the narrative.