しんぎのほど
extent to which (something) is true or false; whether or not (something) is true
Also written 真偽の程
Expression, Noun
彼かれの報告ほうこくの真偽しんぎのほどは疑うたがわしい。
I doubt the truth of his report.
この話はなしは又聞またぎきなので、真偽しんぎの程ほどは分わかりません。
As I heard the story secondhand, I can't ascertain the truth of it.