Is there any idiom or proverb that means "the evidence contradicts what you claim"?
There is a proverb in Persian that says:
"Should/ shall we believe the rooster's tail or the fox's oaths to God?!"
Its etymology is like this:
Once a fox who was passing a village, stole a rooster/cock and put it into his backpack, and ran away. But a villager saw him and informed everybody, so some villagers ran after him and finally got him in a corner. The villagers asked him to give back the rooster to them, but the fox repeatedly was saying:
"I swear to God that I have no rooster with me, I don't know what you are talking about", but he didn't know that tail of the rooster was sticking out his backpack.
So the people replied to him sarcastically and mockingly:
"Should/ shall we believe that rooster's tail or your oaths to God?"
It implies that "the evidence contradicts what you claim" ( i.e., we know that you are lying!) or " your actions contradict your words".
Example:
A famous merchant claims that his business is not doing well, for avoiding paying his taxes, but lives in a mansion and has many other luxurious items under his name. So the officials would say him:
"Mr.___! Should (or shall) we believe the rooster's tail or the fox's oaths? [ Should we believe what you claim (=not having good income) or what we have as evidence (=list of your properties) ?!] Unfortunately, all the evidence contradict what you claim and you should pay your taxes!!"
Is there any idiom or proverb in English that would convey the same connotation?
PS:
This proverb is used among politicians a lot! For example; you can see that its connotation is shown in the following picture. This man is a former president and has stated something about parliamentary elections, but one of his opponents has put this picture in his blog trying to say "the evidence contradicts what you said".