Bhubaneswar, Jan 21 (IANS): A day after the CBI questioned former prime minister Manmohan Singh in connection with the allocation of a coal block to Hindalco, the BJP's Odisha unit Wednesday demanded that Chief Minister Naveen Patnaik also be questioned in the case.

In 2005, Patnaik recommended to the central government to allocate the coal mines to Hindalco, which has set up an alumina refinery and smelter plant in the state.

"Naveen Patnaik should be questioned for recommending the mines in the favour of Aditya Birla Group. While CBI has already interrogated Kumarmangalam Birla and former prime minister Manmohan Singh, the chief minister cannot get away," senior state BJP leader Suresh Pujari told reporters here.

"The questioning of Naveen Patnaik becomes inevitable," he said.

The investigation cannot be completed without questioning the chief minister, he added.

However, the ruling Biju Janata Dal dismissed the demand and said the recommendation was made in the Hindalco's favour taking into consideration the state's interests.

"If one were to go by the BJP's logic, all chief ministers have to be interrogated by the CBI for making recommendations. It is usual that chief ministers make recommendations for allocation of natural resources keeping in mind the interests of the state," said BJD spokesperson Pratap Keshari Deb.

The Congress has, however, tried to downplay the issue of Manmohan Singh's questioning by the CBI.

Leader of Opposition in the Odisha assembly Narasingh Mishra said the former prime minister was "not interrogated as an accused".

"The former prime minister was not interrogated as an accused. Since he also held the additional charge of coal ministry, the CBI questioned him as someone who may have some information relating to the probe," said Mishra.