With wife and now Congress general secretary Priyanka Gandhi in tow, Robert Vadra arrived at the Enforcement Directorate (ED) office in the city in connection with a money laundering case relating to alleged possession of illegal foreign assets.

Sources say more than 40 questions will be put to Vadra and he is required to give written answers for the each of them. Vadra's advocate, however, will be present in an adjoining room.

Vadra was directed by a Delhi court to cooperate with the investigation being carried out by the central probe agency after he knocked on its door seeking anticipatory bail in this case.

A Delhi court last week granted interim bail to him till February 16 and asked him to join probe by appearing in person on February 6 in this case.

The case relates to allegations of money laundering in the purchase of a London-based property located at 12, Bryanston Square worth 1.9 million pounds, which is allegedly owned by Vadra, brother-in-law of Congress president Rahul Gandhi.

The agency had told the court that it has received information about various new properties in London which belongs to Vadra including two houses of five and four million each, six other flats and more properties.

"We just want him to come and inform about his properties," the ED counsel had said in the court.

In his anticipatory bail plea, Vadra had said he was being subjected to "unwarranted, unjustified and malicious criminal prosecution which on the face of it is completely politically motivated and is being carried out for reasons other than those prescribed under law".

The ED had carried out raids in this case in December last year at premises of a firm linked to Vadra in Delhi. It also grilled his associate Manoj Arora in connection with the case.

Vadra had alleged he was being "hounded and harassed" to subserve political ends.