These ironclad details are irrefutable proof in black and white.

白纸黑字，铁证如山。

《新英汉大辞典》

He's going to need some irrefutable proof before he'll be willing to bend.

他只会在不可辨驳的证据下才会愿意屈服。

youdao

"There was never irrefutable proof that this happened but I heard that money had changed hands," says a western diplomat who was serving in Gabon at the time.

当时在加蓬工作的一位西方外交官称，从来没有确凿的证据证明有贿赂行为，但我听说钱有这样的事。

youdao

The irrefutable proof of excess demand is that universities pay legions of employees to turn down perfectly good business.

FORBES: School For Scandal

But although there was plenty of circumstantial evidence - and a working assumption that the RUF could not have done what it did without rear bases in Liberia - few people would claim to have irrefutable proof.

BBC: The case against Taylor