New Delhi/Patna, Sept. 7: The CBI has summoned RJD chief Lalu Prasad and his son Tejashwi Prasad Yadav in connection with the alleged rigging of a railways hotel tender process in exchange for three acres of prime land in Patna.

The case dates back to 2004-2009 when Lalu was the railway minister during UPA-I. 'Lalu Prasad has been asked to appear before the investigating team in Delhi on September 11, while his son has been summoned on September 12,' said a senior CBI official.

The summonses from the CBI almost coincide with the September 10 Srijan Scam Yatra which Lalu and Tejashwi are scheduled to kick off in Bhagalpur - the epicentre of the over Rs 1,000-crore scam involving fraudulent transfer of government money and an issue which the RJD wishes to use as a stick against chief minister Nitish Kumar and deputy chief minister Sushil Kumar Modi.

The CBI has already filed an FIR against Lalu, Tejashwi and others and had raided their 10 Circular Road residence in this connection. The incident triggered the collapse of the Grand Alliance government in Bihar.

'Questioning accused persons is a natural process,' said deputy chief minister Sushil Kumar Modi today, denying any motive over the time of questioning.

The case pertains to rigging a tender process in 2005-2006 to award the sub-lease of railway hotels in Ranchi and Puri to hoteliers in exchange for three acres of prime land in Patna routed through a benami company.

Besides Lalu, his son Tejashwi and wife Rabri Devi and others have been booked for cheating, criminal conspiracy and under provisions for Prevention of Corruption Act. Lalu, a staunch critic of Prime Minister Narendra Modi, had alleged the CBI's case against him and his family members were part of 'politics of vendetta.'

In May, the Income Tax department had raided 22 premises in Delhi, Gurgaon and Rewari in Haryana in connection with the benami land deals of Lalu Prasad.

The raid had come in the wake of the BJP's allegation that the former Bihar chief minister's daughter and his two sons were involved in benami land deals to the tune of Rs 1,000 crore. The party had demanded a probe by the Centre and alleged that the land deal dated back to 2004 when Lalu was the railway minister.

Sources in the agency said the tender process was rigged and manipulated and the conditions were tweaked to help the private party (Sujata Hotel). In return, three acres in western Patna were given to Delight Marketing, which is known to the family of Lalu Yadav, at a very low cost. Subsequently, between 2010 and 2014, this land was transferred to another company, Lara Projects, which is owned by Lalu Yadav's family members.