India's prime minister has hit back at critics of his graft-tainted government, stressing his own "high standard" of personal integrity and lauding his administration as a beacon of transparency.

In an interview yesterday in the Hindustan Times newspaper, Manmohan Singh also argued that the Indian economy was healthier than media "pessimism" suggested, and promised further measures on tax issues that have rattled foreign investors.

Singh rarely grants media interviews, but has ramped up his public statements since taking on the finance ministry portfolio last month, in what analysts see as an effort to secure his legacy.

Singh is not expected to continue as premier after elections in 2014 and his personal reputation has taken a beating during his second term, amid a series of high-profile corruption scandals and accusations of policy drift.

"Coming to the personal criticism, not only have I maintained a high standard of integrity in my conduct, I have endeavoured to raise the levels in the system as well," Singh said.

Citing legislation like the Right to Information Act and a Whistleblowers Bill, the premier said his administration had made important strides in improving official accountability that would benefit future generations.

"Never before in the history of India have so many steps been taken in such a short time to bring in transparency into the functioning government, make government accountable to the people for its actions and bring in measures to control corruption," he said.

Singh's ruling coalition has been embroiled in a series of scandals.

Singh, who as finance minister in 1991 was credited with opening the Indian economy after decades of quasi-socialist planning, took over the ministry again last month, after Pranab Mukherjee quit to run for president.