This Q&A mention accusations of plagiarism levelled at T. S. Eliot's famous poem "The Waste Land". There seems to be a lot of information about this on the internet, but I couldn't easily distil the important points to understand what's going on here. What was the origin of these accusations? How prevalent have they been, and how much credit should we give them? What's the evidence for and against "The Waste Land" being plagiarised, and from whom?

This Q&A mention accusations of plagiarism levelled at T. S. Eliot in the context of his famous poem "The Waste Land". There seems to be a lot of information about this on the internet, for example Plagiarism Today and the linked Cracked article, but I couldn't easily distil the important points to understand what's going on here. What was the origin of these accusations? How prevalent have they been, and how much credit should we give them? What's the evidence for and against "The Waste Land" being plagiarised, and from whom?