Bhubaneswar, Feb 20 (IANS): The Odisha Crime Branch which is investigating the murder of state minister Naba Das, said on Monday that it wants to conduct a comprehensive psychological evaluation of accused Gopal Krishna Das at the Nimhans in Bengaluru.

In a statement on Monday, the crime branch (CB) said the accused had a prolonged history of mental illness and for that, a special medical board was constituted consisting of four psychiatric experts.

The board examined the accused and carried out the analysis at Jharsuguda.

The board later opined that there is a need to have a detailed examination of the accused to come to a definite conclusion about his mental health, it said.

As per the advice of the medical board, the CB on Monday appealed to a Jharsuguda court for a comprehensive mental evaluation of Das at Nimhans.

However, the court has rejected the appeal, the Crime Branch said.

"We have applied for the certified copy of the order, and after availing the copy, the same will be examined by the legal cell crime branch and if required, the CB will move to the higher forum," it said.

Naba Das was killed by sacked Assistant Sub Inspector of police Gopal Das on January 29.

Gopal Das had fired a bullet at the chest of the minister from very close range.

Though the police arrested the accused from the spot, the motive behind the murder was yet to be known.