As per sources, the ED asked over 36 questions from Vadra in the 5.5 hour long questioning; and he is likely to undergo another round of questioning on the same on Thursday.
Vadra's wife Priyanka Gandhi accompanied him in a white Toyota Land Cruiser and dropped him outside the ED's office in Jamnagar House, a move seen as sending a political message to Congress's opponents ahead of Lok Sabha polls.
Vadra left the office at about 9:40 PM alone in the same car in which Priyanka had dropped him.
His lawyer said Vadra has replied to every question that was put to him.
"All charges against him are wrong. We will cooperate with the agency 100 per cent. He will come whenever he is called," Suman Jyoti Khaitan, his lawyer told the mediapersons waiting outside the ED office.
Officials said Vadra has been called again Thursday.
Priyanka, shortly after dropping her husband, took charge as AICC general secretary in-charge of Uttar Pradesh East, after her formal induction into the Congress party on January 23.
"He is my husband, he is my family...I support my family," Priyanka said in a show of support to Vadra, who returned from London earlier in the day.
Priyanka was asked by newsmen at the All India Congress Committee headquarters whether she was sending any message by dropping her husband at the ED office.
Asked if it was a political vendetta, she said everyone knows why this is being done.
On the day of Priyanka's appointment, Vadra had sent an emotional message to her. "Congratulations P... always by your side in every phase of your life. Give it your best," Vadra said in a Facebook post.
It is for the first time that Vadra, son-in-law of Sonia Gandhi, is appearing before any probe agency in connection with alleged criminal charges of dubious financial dealings.
After wading through a posse of assembled mediapersons, Vadra entered the ED office at around 3:47 pm, minutes after a team of his lawyers reached the premises. He then signed the attendance register before being taken in for questioning.
Vadra has denied allegations of possessing illegal foreign assets and termed them a political witch hunt against him. He has alleged he was being "hounded and harassed" to subserve political ends.
Ahead of the questioning by a team of three ED officials, official sources said Vadra was put through a dozen questions on transactions, purchase and possession of certain immovable assets in London and his statement was recorded under the Prevention of Money Laundering Act.?