India's 'high-calibre satellite' imagery has not shown diversion of Brahmaputra waters by China, official sources said in New Delhi on Thursday responding to criticism that government was turning a 'Nelson's eye' to reports of massive construction plans by Chinese authorities.

India has ascertained from its sources that the construction of a dam at Zangmu in the middle reaches of the Yarlung Tsangpo (as the Brahmaputra is called in Tibet) is a run-of-the river hydro-electricity project which does not store water and will not adversely impact the downstream areas in India, the sources said adding there was no cause for "worry or alarm".

However, the sources said the government was continuing to "assess and monitor" the situation and any attempt to divert the water in future will not be "seen favourably" by India.

Noting that apart from the assurances from China that it is a run-of-the river project, the government has "verified" the facts from its own sources, the sources said adding "we don't only trust but also assess."

They also said a large proportion of the catchment of the Brahmaputra was within Indian territory.

"It is important that the states of Arunachal Pradesh and Assam harness and utilize the waters of the Brahmaputra.  This is the really important issue," they said.

The sources also pointed out that there was exchange of water data between the two countries and there was an expert-level committee to discuss such issues.