Nepal's anti-graft commission has filed charges against five former ministers and other ex-government officials in a case alleging multi-million-dollar corruption in a major airport construction project.

The charges, submitted on Sunday, come three months after anti-corruption protesters overthrew the government and set parliament on fire.

Documents released by the Commission for the Investigation of Abuse of Authority (CIAA) said that "the public servants involved in the project, knowingly and maliciously, increased the cost estimate" of the China-backed Pokhara airport project.

The CIAA said the 55 individuals involved had inflated cost estimates by around $75 million, taking the approved cost of the project from $169 million to $244 million.

Those named include a former finance minister, four former heads of the ministry overseeing civil aviation, and 10 former civil service secretaries.