This was erected into a special delict in the troubled times of the Roman Republic, and the rules became a permanent part of the law.
Hence it was said to be mixta by some jurists and Justinian so decides, but it had the main characteristic of penal actions that it was not available against the heirs of the wrongdoer.
Thus we are told that what could be recovered was a multiple of the verum pretium, not of the interest the aggrieved had in the thing (interesse), but as one text tells us this of furtum also, the import is doubtful.
[1] One text suggests that mere encouragement was enough to make a man liable for ope consilio, which is consistent with the genesis of the action.
Probably in classical law it was barred by actio furti, but under Justinian it was still available for any excess recoverable by it.