A database that tracks companies and people tied to bribery has been effective in helping authorities clean up bidding for major projects, the Supreme People's Procuratorate said on Wednesday.

The system, established in 2011, allows authorities to inquire whether a company or individual has a bribery conviction. If so, they are likely to be disqualified from bidding for major projects, the SPP said.

Figures provided by the SPP show that inquiries were conducted last year into more than 4 million organizations and 5 million individuals.