Kolkata, June 26 (IANS): The BJP on Friday demanded explanation from the Congress over former IPL chief Lalit Modi "bumping" into Congress president Sonia Gandhi's daughter Priyanka Vadra and her husband Robert Vadra in a London restaurant last year.

"Happy to meet the Gandhi family in London. I had run into Robert (Vadra) and Priyanka separately in a restaurant," tweeted Lalit Modi, who is embroiled in a row over alleged financial irregularities.

Reacting over the issue, Bharatiya Janata party national secretary Siddharth Nath Singh said the Congress owed an explanation.

"The Congress cannot escape from their liability by calling Robert and Priyanka Vadra's meeting with Lalit Modi as incidental. They need to clarify about the meeting," he told media persons here.

Siddharth Nath Singh also frowned upon the opposition for attacking the BJP by relying on documents provided by Lalit Modi.

"The entire opposition is trying to do politics on the basis of documents given by an absconder. The opposition needs to realise how far can they rely on documents given by an absconder," said Siddharth Nath Singh reacting to the Congress releasing a copy of an affidavit signed by Rajasthan Chief Minister Vasundhara Raje which allegedly favoured Modi's immigration application.

The opposition has been demanding the resignations of External Affairs Minister Sushma Swaraj and Raje over the Lalit Modi controversy.