A team of senior income tax (I-T) officials from New Delhi landed in Patna on Tuesday and questioned RJD chief Lalu Prasad's wife and former chief minister Rabri Devi, daughter Misa Bharti and son Tejashwi Prasad Yadav in connection with assets disproportionate to their income, as well as benami (disguised) property and transactions worth Rs 1,000 crore.

According to official sources, the interrogation focused on three main issues - disproportionate assets, benami deals and post-demonetisation transactions.

Earlier in June, the I-T department had asked the Bihar government to furnish details about land deals executed by or registered in the name of Rabri, Tejashwi and his brother and former health minister Tej Pratap Yadav in connection with an ongoing investigation.

The suspicious land transactions related to Lalu and his family members were first raised by senior BJP leader Sushil Kumar Modi in the first week of April.

He has alleged that they own property worth around Rs 1,000 crore, and has made frequent "disclosures" on the matter, supporting them with documents related to use of shell companies to mask such transactions.

Tuesday's questioning was conducted at the third floor of the I-T headquarters for Bihar and Jharkhand. Tejashwi, the former deputy chief minister, was the first to appear before the officials around 10.30am, while Rabri and Misa came around 2pm.

They were questioned on various aspects of assets owned by them till 6.45pm amid several rounds of snacks and tea served by the taxmen.

"All the three RJD leaders were summoned with strict directions to appear before the officials here on Tuesday. They had been asked to come on an earlier date, but they had expressed their helplessness in doing so because they were busy preparing for a rally being organised by their party in Patna on August 27," an I-T source told The Telegraph.

A tax official said the team from New Delhi was assisted by their Patna counterparts.

"A detailed questionnaire was brought by the New Delhi team and answers, as well as statements, of the three persons suspected to be involved in having assets disproportionate to their income, as well as benami transactions were thoroughly recorded," a senior I-T official said on the condition of anonymity.

The building was heavily guarded by police officials and private security guards and they tried their best to keep RJD supporters and media persons outside its premises.

The department is also expected to file a complaint in a competent court against the Lalu Prasad family in this case.

The taxmen had earlier questioned Misa, who is a Rajya Sabha member, and her husband Shailesh Kumar in New Delhi over their alleged involvement in benami transactions through which they acquired farmhouses in the national capital.

The I-T department had, on June 20, attached over a dozen properties in New Delhi and Patna belonging to Rabri, Misa and Shailesh, Tejashwi, Ragini and Chanda - two other daughters of Lalu.

The book value or transaction value of the property is around Rs 9 crore, but their market value is around Rs 175 crore to Rs 180 crore.