The chairman of that meeting had said the matter would be taken to the minister concerned, who would charter the future course, Santhanam recounted.

He was answering a query on why he chose to go public after so many years. 'The impression that suddenly the jack-in-the-antique box is up, is not based on facts,' he said.

The scientist also released photographs of 'ground zero' of the thermonuclear device, which showed that there was no crater after the explosion. There should have been a crater of 72 metres radius if the device had been successful, he said.

'This picture tells a story that we have to do more honest homework in the direction of improving our thermonuclear design,' said Santhanam.

Asked if the depth of the shaft made a difference to the crater size, he indicated that while he could not reveal the exact measurements, it was sufficient to create a substantial crater.

Santhanam said that the radio-chemical analysis of the test was classified and had not been shared with the scientists.

Former science advisor to prime minister Indira Gandhi, Ashok Parthasarthi said by questioning the results 'the intention was not to denigrate the nuclear weapons programme, but to set the matter right'.

'We have to have a credible nuclear weapons deterrent. We have already lost time,' said Parthasarthi, who was involved in Pokhran-1 test in 1974.

India tested five nuclear devices in May 1998, including the thermonuclear device.