Complying with the Supreme Court directive, the Central Bureau of Investigation on Monday began the probe against Uttar Pradesh Chief Minister Mulayam Singh Yadav and some of his family members to probe alleged amassing of property disproportionate to their known sources of income.

The preliminary enquiry has been registered against Yadav and some of his kin in compliance of a Supreme Court order, the CBI said.

The agency, after procuring the Supreme Court order on March 3, studied it over the weekend after which a PE was registered on Monday evening, the sources said.

The apex court order came on a PIL filed by Vishwanath Chaturvedi, a UP resident and advocate who had alleged the Samajwadi Party chief and his kin had amassed wealth by illegal means and by misusing their power and authority.

To begin the probe, the CBI would be going through all the documents of the sale deeds and other statements filed by the parties along with the PIL in the Supreme Court.

The CBI could take the assistance of chartered accountants, engineers and certified valuers for evaluation of properties as listed in the PIL.