CID Episode No- 50

A space program researcher is killed in his hotel suite in a very planned manner. CID gets on the case, only to be hit with a realization that this man was no regular researcher - he was a spy who was selling sensitive information to the enemies of the country. Just before his death, few people visited him & are prime suspects. Further, while cops try to find out the culprit, they come across another murder. Who is behind these killings & what was the motive?