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 felt that he was on the verge of identifying who had ordered the hit on the Musas, and was collecting irrefutable proof, which he intended to present at the International Criminal Court.

他感觉就快要找出袭击穆萨父女的幕后元凶了，他正在搜集无可辩驳的证据，并打算向国际刑事法庭呈交这些证据。

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