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Investigators claim that Robert Vadra, directly or indirectly, owns nine properties in London cumulatively worth around 12 million pounds. Three of these are villas, the rest, luxury flats. All these were purchased between 2005 and 2010, when the UPA government was in power.
The allegations of money laundering involve the purchase of a mansion at 12, Bryanston Square in London, which has an estimated value of 1.9 million pounds. Robert Vadra has also been battling allegations of shadowy land deals in Haryana and Rajasthan.
In a Facebook post, Mr Vadra said he was "truly heartened that truth prevailed today". "My unwavering faith in the judicial system has been vindicated," he added.
Referring to the investigation against Robert Vadra, Congress chief Rahul Gandhi has said the government "should not be selective". Mr Gandhi has sought an investigation against Prime Minister Narendra Modi in the Rafale jet deal.
Priyanka Gandhi Vadra -- Robert Vadra's wife and a general secretary of the Congress -- has told reporters that for her, it is "family first". She was seen dropping off or picking up her husband multiple times during his questioning.
Special judge Arvind Kumar granted the relief to Mr Vadra for a personal bond of Rs 5 lakh and a surety of the same amount. He is not allowed to leave the country without permission.
Sources say the investigators claim to have documents that prove that Mr Vadra had paid for the repairs and maintenance of the property at London's Brynstone Square.
The documents include e-mails between Mr Vadra and Sumit Chadha. One Manoj, referred to in the e-mails, is Manoj Arora, a former employee of Skylight Hospitality -- a firm linked to Mr Vadra. The money-laundering case was initially filed against him.
Sumit Chadha is the London-based relative of controversial arms dealer Sanjay Bhandari. Robert Vadra has so far denied knowing Sanjay Bhandari. To establish his links with the arms dealer, investigators have shown him various documents.
Last month, Mr Vadra indicated his keenness to join active politics and indicated that his constituency of choice is Moradabad. Later he clarified that he would like to serve people only after he is cleared of all charges. Posters had mushroomed in Ghaziabad, Uttar Pradesh and Haryana's Sonepat, urging him to contest the upcoming national election.