Do not deny a monetary claim
“Do not deal falsely” Vayikra 19:11
This is a warning against the denial of articles of value worth a coin of minimal amount and above.
It includes all kinds of monetary matters-
Something entrusted for safekeeping, a loan, whether he robbed or cheated him, a lost object that has not been returned.
If he was sued for it and he gave a false denial, he violates this prohibition and becomes disqualified from being a witness.
This applies in all places at all times.