There’s no smoke without fire 英文諺語
There’s no smoke without fire 無風不起浪；有煙必有火；事出有因
If people are saying that someone has done something bad but no one knows whether it is true, it probably is true. There is usually some truth behind every rumor.
Also,where there’s smoke there’s fire. A suspicion or rumor usually has a basis in fact, as in When the sales figures continued strong but the company still wasn’t making money, he suspected something was wrong—there’s no smoke without fire. First stated in the late 1300s, this expression appeared in numerous proverb collections from 1546 on and remains current today.
“She claims that they were just good friends and that they never slept together but there’s no smoke without fire, that’s what I say.”