New Delhi:�Himachal Pradesh Chief Minister Virbhadra Singh was today questioned for the second consecutive day in connection with an alleged disproportionate assets case against him. Singh arrived at agency headquarters at around 11 AM today for the second round of questioning. He was grilled by CBI for over seven hours yesterday. Agency sources had claimed that he failed to offer any explanation when confronted with "evidence" against him. "CBI has a fool proof case against him, his associates and partners in criminal conspiracy regarding the assets acquired in the name of his children and wife," an official had said. The agency had initiated an inquiry which had allegedly showed that Singh, while serving as Union Minister during 2009-2012 (UPA rule), had accumulated assets worth Rs 6.03 crore (approx) in his name and in the name of his family members which were found to be disproportionate to his known sources of income, CBI has said. The FIR filed with a designated court in Delhi under the Prevention of Corruption Act, named Singh, his wife Pratibha Singh, LIC agent Anand Chauhan and owner of Universal Apple Associates Limited Chunni Lal Chauhan. The allegations have been strongly refuted by Singh. In a statement, CBI spokesperson had alleged that Singh had invested his unaccounted income in LIC policies in his name and in the name of his wife and other family members through a private person by showing the same as agricultural income. "This was done by creation of MoU purportedly dated June 15, 2008 for maintenance of an apple orchard, with the said private person (Chauhan) for a period of three years. "The private person had allegedly deposited Rs five crore cash (approx) in his own bank account and debited the same through cheques for purchasing various LIC policies in their names," CBI had said. It had said Singh allegedly attempted to legitimize the same as agricultural income by filing revised Income Tax Returns in 2012. "The agricultural income as claimed by him in his revised ITRs was not found to be tenable. The then Union Minister had allegedly accumulated other assets disproportionate to known sources of income," CBI has alleged.