pretext; history; past; story
according to ...; ... says
この建物にはいわくがあると聞いた。
I heard this building has a dark history.
彼は笑みを浮かべながらいわくありげな話を始めた。
He started telling a mysterious story with a smile on his face.
いわくつきの品物を安易に買うべきではない。
You should not casually buy items with a dubious background.