Officials privy to the probe said the order was issued against a firm allegedly involved in the case--AB Exports Private Limited-- and also alleged that Prasad's relatives were the "beneficiaries" of the immovable properties of this firm.
A property in south Delhi's New Friends Colony is owned by this firm, they said.
A provisional order for attachment--under the Benami Transactions (Prohibition) Act, 2016-- was issued by the department in June this year and now the order has been confirmed after adjudication, they said.
The cases of other assets which were provisionally attached in June will also be processed similarly, they added.
The department had earlier served notices of attachment of assets to Prasad, Bihar's ex-chief minister, his wife Rabri Devi, also a former CM, son Tejashwi Yadav, former state deputy CM, daughters Chanda, Ragini Yadav and Misa Bharti, an MP, and son-in-law Shailesh Kumar.
The tax department had attached about a dozen plots and buildings in Delhi and Bihar including a farmhouse and land in the Palam Vihar area, a building in the upmarket New Friends Colony area of south Delhi, nine plots on a 256.75 decimal land area in Patna's Phulwari Sharif area, where a shopping mall was being constructed, among a few others in the same area in Bihar's capital.
The department has said these alleged benami assets bear a "deed" value of about Rs 9.32 crore but the taxman has estimated their current market value at Rs 170-180 crore.
Benami properties are those in which the real beneficiary is not the one in whose name (benamidar) the property has been purchased.
The Prasad family has said the cases are the outcome of a "political vendetta" against them.
The Act allows for the prosecution of the beneficial owner, the benamidar, the abettor and the inducer to benami transactions.
Under the provisions of the Act, assets held benami after the final prosecution are liable for confiscation by the government without payment of compensation.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)