External affairs minister Salman Khurshid told reporters that he felt "sad at the way it ( Aam Aadmi Party) is playing with India's relations" with other countries.
External affairs ministry spokesperson Syed Akbaruddin tweeted: "Uganda's high commission. Staff currently not in New Delhi. Please do not give credence to rumours."
AAP chief minister Arvind Kejriwal told people at a protest demonstration that an "official" of the Ugandan high commission had given Bharti a letter substantiating their claim that some African women were involved in a "drug and prostitution racket".
The letter spoke of a Ugandan woman who was allegedly "duped" on pretext of a job offer here and forced into prostitution.
Bharti has attracted flak for his vigilante-style midnight raid in Khirki Extension area of south Delhi targeting a "drug and sex racket" among African nationals living there.
Some Ugandan women had been rounded up and taken for a medical examination, leading African envoys to voice their concern. India had to reach out to the African envoys assuring them that the incident was an "aberration".
Khurshid said the letter was written in June 2013. He said he "cannot think of anything greater in terms of betrayal of this country than what is being done".
Kejriwal, while brandishing the letter, had claimed the "official" had praised Bharti's raid on Wednesday midnight.
The letter is purportedly written by the defence advisor of the Ugandan high commission on June 19, 2013 to the chief of military intelligence in Kampala.