New Delhi, Sep 7 (IANS) Calling Homi Sethna a 'pillar of India's nuclear energy programme', Prime Minister Manmohan Singh Tuesday in a condolence message praised the eminent scientist for his immense contribution to the country's energy security.

'Dr. Sethna was a brilliant nuclear scientist and an exceptional human being,' Manmohan Singh said in a message to the nuclear scientist's family.

'His contribution to the development and production of nuclear materials and thereby to the country's efforts to build energy security is immense. He was a pillar of India's nuclear energy programme in the early years,' said the prime minister.

'He was widely respected and admired and had the ability to inspire young scientists to give their best in the national cause. His life's work is a saga of dedication, brilliance and patriotic public service,' he said.

The 86-year-old Sethna, former chairman of the Atomic Energy Commission, passed away at his Malabar Hills residence in Mumbai Sunday night. His last rites were performed Tuesday.

The legendary nuclear scientist played a pivotal role in India's first peaceful nuclear explosion of May 18, 1974, called the Smiling Buddha, or Pokhran-I.

Recalling his personal memories of the iconic nuclear scientist, the prime minister said he 'benefitted greatly from his deep knowledge, insight and vision'.

He has left behind a void that would be very difficult to fill, the prime minister said.