Singh (86) breathed his last at AIIMS this evening.
He is survived by wife and two sons.
Singh was Deputy chairman of Bihar State Planning Board.
He had seved as Minister of State for External Affairs in the V P Singh government and as India's Ambassador to Syria during I K Gujral's time.
Singh was elected as a Lok Sabha member thrice from Sheohar in Bihar.
Chief Minister Nitish Kumar condoled the death of Harikishore Singh and described him as a "socialist" leader who actively participated in social welfare programmes.
