Parts of the letter were published in a column by Chris Elliott, the newspaper's reader's editor, or ombudsman.
Hussein Amin, who says he is running for parliament in 2016, is one of the more than 30 children Amin is said to have fathered. The Guardian reported that he is the son of the late Ugandan leader's fourth wife, Kay.
Hussein Amin's concerns about the obituary included the number of people whose deaths were blamed on his father; his role in Britain's Burma campaign during World War II; whether he participated in the massacre of Turkana nomads; and his date of birth.
The Guardian's full piece is worth reading, and is available here, but one fact jumped out at us: Hussein Amin's concerns about his father's victims. The original obituary had this to say:
"The death toll during the Amin regime will never be accurately known. The best estimate, from the International Commission of Jurists in Geneva, is that it was not less than 80,000 and more likely around 300,000. Another estimate, compiled by exile organizations with the help of Amnesty International, put the number killed at 500,000."
But Hussein Amin, citing the ICJ, notes that the number was lower — between 30,000 and 80,000.
"I am not sure if you can take this from Idi Amin's son however factual my criticism is," Hussein Amin's letter says, according to The Guardian.
The newspaper's Elliott adds:
"The readers' editor's office always considers a complaint seriously, from wherever it comes. The son of the principal is always worth listening to, although that relationship does not guarantee the complainant will always be right."
Elliott said the newspaper investigated the 15 areas where Hussein Amin alleged inaccuracies in his father's obituary, adding the original obituary "was supported by all the major sources we consulted and so we shall not be revising it online, although we respect Hussein Amin's different view of his father's history."