What is the ruling on one who conceals a transgressor and advises him without informing the competent authorities?

It is permissible to conceal the sin of someone who is not habitually committing it, and they should be advised and warned against returning to it. However, if the person is a transgressor, their responsibility is not cleared except by reporting their matter to someone who can punish them. And if the sin relates to the rights of a human being, such as theft, adultery, or murder, then it is not permissible to conceal it; rather, one must testify against them to uphold rights.