Priti Patel has insisted Rwanda is a "safe" country, despite warnings from Foreign Office officials of torture and killings.
Court documents revealed officials in the Foreign, Commonwealth and Development Office (FCDO) had concerns about the plan to send illegal migrants to the African nation.
One FCDO worker said torture and "even killings" are accepted in Rwanda.
But Ms Patel said: "Well, actually, Rwanda is a safe country. All our work has shown that and the government-to-government work has shown that too."
The UK high commissioner to Rwanda in 2021 warned that the country "has been accused of recruiting refugees to conduct armed operations in neighbouring countries".
It comes after figures showed more than 3,600 migrants crossed the Channel to the UK in July, the highest monthly total this year.