The bond between Gandhi and Hermann Kallenbach has been a subject of speculation and gossip for years owing to their closeness, with previously published correspondence suggesting they may have had a physical relationship.
One of the handwritten letters from Gandhi to Kallenbach that went on show on Wednesday, the 65th anniversary of Gandhi's assassination, is addressed to "My dear Lower House" and signed "Sinly yours, Upper House".
However scholars looking for clear evidence on the full extent of the men's relationship were left disappointed, with curators acknowledging that they had only put a sample of correspondence on display at the National Archives museum.
"These are original letters and we have provided a sample of the correspondence between Gandhi and Kallenbach.
There is a lot that is new and significant," Mushirul Hasan, chief of the National Archives, said.
Gandhi lived with Kallenbach, a German-born Jewish architect, in Johannesburg for about two years from 1907 before returning to India in 1914 where he helped unify the gathering political movement against British colonial rule.
The archive of letters and photos belonging to Kallenbach was purchased by the Indian government last year, just before they were due to be auctioned by Sotheby's in London.
Hasan denied that the collection had been screened and controversial letters left out keeping in mind the exalted status that Gandhi enjoys in the country.
"Nothing controversial has been left out or necessarily included," Hasan said.
"They had a marvellous relationship and the archives reveal the intensity of that relationship."
The relationship between Gandhi and the wealthy South African was most recently chronicled in a book by former New York Times editor Joseph Lelyveld.
Lelyveld was forced to defend his book against accusations that he had suggested Gandhi was bisexual. "The word 'bisexual' nowhere appears in the book," he wrote afterwards.
Raj Bala Jain, part of the National Archives team that studied the collection in detail, said she was surprised how their relationship had been misconstrued.
"I do not know from where he (Lelyveld) quoted those letters. I did not find even a single letter with sexual overtones," she said.
"Friendship can be misinterpreted. I think Gandhi was very normal and above such things," she said of the man who took a public vow of celibacy in his 30s, adding it was not possible to display all correspondence between the two.
"We have displayed what we thought was most interesting."
Among other documents were dozens of letters written by Gandhi's sons to Kallenbach that provide details of his life after his return to the country from South Africa.
In one of them, Harilal, one of the four sons of Gandhi, complains to Kallenbach about how his father had "neglected us". "For my failures in exam I hold him responsible," he wrote.
India has in the past fretted about private auctions of Gandhi's belongings, saying that they insult the memory of a man who rejected material wealth. Auctions of Gandhi's personal items like spectacles and other memorabilia often raise an uproar in the country where many people feel the items are part of the country's cultural legacy.
"We are talking about Gandhi. Such emotions are justified considering the glory that he brought to India," said Hasan.