Eminent scientist R A Mashelkar on Saturday resigned as head of a technical expert committee that looked into patents amendments.
In a letter faxed to Industrial Policy and Promotion secretary Ajay Dua, Mashelkar said he was "deeply pained by the fact that doubts, explicit or implicit," have been expressed about his "integrity, competence and motives."
In the light of "personalised attack," Mashelkar said he was relinquishing the position of committee chairman and had dissociated completely from the technical expert group on patent law issues.
He had retired as director general of the Council for Scientific and Industrial Research last year.
Mashelkar said he had headed 12 high-power committees, looking into issues ranging from the Bhopal gas disaster to spurious drug menace and national auto fuel policy but never had such an experience.
"Never before have I had such an unfortunate experience," he said, adding that the four colleagues in the technical expert group, whose eminence and integrity were beyond any question, could undertake the remaining task.
Despite pressure from the Left, pharma firms and NGOs, the government had permitted the expert group to remove "technical inaccuracies" from his controversial report on patent laws, Mashelkar said.