The Political and Economic Risk Consultancy (PERC) has ranked India as the sixth most corrupted country in the Asia-Pacific region with a score of 7.18 out of the worst possible 10 in its annual survey that covered 14 countries, as well as Hong Kong and Macau.
Indonesia was ranked the most corrupt regional nation with a grade of 9.27, followed by Cambodia (9.10), Vietnam (8.7), the Philippines (8.06) and Thailand (7.60).
Singapore remained top of the list with a score of 1.42, while Australia was second with 2.28 and Hong Kong third with 2.67.
Zero means the country or territory is seen to suffer the least corruption among politicians and civil servants, PERC said in the report.
The Hong Kong-based consultancy said Indonesian lawmakers' call for a criminal probe into the Yudhoyono government's bailout of Bank Century in 2008 reflected attempts by a corrupt establishment to maintain the status quo.
"Corruption has become a charge being used by corrupt people to protect themselves and to stifle reform," PERC said.
"The whole fight against corruption is in danger of being corrupted," it said.
PERC's poll was conducted from December to February, and involved 2,147 mid-level and senior Asian and expatriate business executives working in the 16 economies.
The United States - included for comparison purposes - was fourth with a score of 3.42, followed by Japan (3.49), Macau (4.96), South Korea (5.98), Taiwan (6.28), Malaysia (6.47) and China (6.52).
"Measuring the level of corruption (in China) is nothing more than guesswork," PERC said.
"What is fairly clear is that the problem of corruption is more severe at the local level of government and business, particularly state-owned enterprises, than at the national level, although there are plenty examples of graft at the national level too," it said.
''The perception that corruption is especially bad in Indonesia will make it more difficult for the country to attract foreign direct investment,'' the PERC report said.
In February, a survey by Transparency International also said that corruption was a fixture in countries like Egypt, India, Indonesia, Morocco and Pakistan, where 60 per cent of executives surveyed reported having been solicited for a bribe.
In its list, New Zealand came in first with a score of 9.4, with Denmark in second with a score of 9.3 and the US was 19th with a score of 7.3.
Transparency International warned that excessive pay, opaque financial structures and offshore havens from financial regulation all work to undermine honesty throughout the system.
"When high-level executives award themselves extraordinary pay packages, lower-level managers may be tempted to sweeten their own pay package by soliciting bribes from suppliers," the organisation said.