Former ISRO Chairman G Madhavan Nair on Friday termed as "very disturbing" the top aerospace scientist Roddam Narasimha quitting as member of the Space Commission where he was serving for more than two decades, and slammed the Department for being "insensitive".

"It's a very disturbing news and it's very unfortunate", Nair said. "He has been a veteran in the space field.

He has contributed to the space programme right from SLV-3 days when (A P J Abdul) Kalam was managing it, till the recent GSLV".

"He (Narasimha) is the only qualified person in the Space Commission. It's unfortunate that we lost his services because of the inaction by the Department of Space", he added.

"The Department of Space is insensitive to any of these things. So it's a very, very unfortunate situation",Nair said.

Asked about the reason for Narasimha's resignation, he said: "I understand he was totally upset by the way the Government has taken action (against four former ISRO scientists, including Nair, last month based on two official committee reports on the controversial Antrix-Devas deal).

Chairman of Space Commission and ISRO and Secretary in the Department of Space, K Radhakrishnan, chose not to react to the development.

B K Chaturvedi and Narasimha probed various aspects of the agreement and their report said, concerns of cheap selling of spectrum to Devas have no basis whatsoever.

But a five-member high-level team, chaired by Pratyush Sinha, found "...not only serious administrative and procedural lapses but also suggestion of collusive behaviour on the part of certain individuals....", and concluded that the four former ISRO scientists, including Nair, were responsible for various acts of commissions.