Russian and Chinese millionaires can buy access to British passports by exploiting a flawed Home Office scheme fast-tracking the super-rich, an investigation has revealed.

Legal and financial advisers were filmed boasting about their role in securing scores of “golden visas” for millionaire foreign clients and offering to omit sensitive details from immigration officials, such as links to the inner circle of the Russian president, Vladimir Putin, and to the Chinese military.

The advisers told an undercover reporter they had helped secure golden visas for a member of the Gadaffi family, the son of a corrupt Thai government minister, an Egyptian charged with corruption, an Eritrean with possible links to military deals in Angola and millionaires from Iran and Iraq whose businesses were affected by sanctions.