プログレッシブ和英中辞典(第4版)の解説
いっせつ【一説】
〔一つの説〕a view；〔別の説〕another view；〔別のうわさ〕another report
一説によると彼は部下に殺されたということだ
There is 「another version of the story [another report] which holds that he was killed by one of his followers.
それもまた一説だ
That's another opinion.／Some people think so.