KUALA LUMPUR, Sept. 23 -- Malaysia does not have a specific house-arrest law. Yet the Prisons Department already has powers that can, under certain conditions, allow prisoners to remain outside prison while their sentences are still running.

That distinction has come into focus after former prime minister Datuk Seri Najib Razak was granted a conditional pardon on September 18 allowing him to serve the remainder of his SRC International jail sentence under house arrest until August 23, 2028, subject to payment of a RM50 million fine and other conditions.

How does the arrangement work? What powers do the prison authorities already have, how is that different from a royal pardon, and what happens to Najib's separate 1MDB sentence?

Here is...