[A pesky situation, this is. But seeing that familiar light in the young man's eyes makes van Zieks all the more determined to crush any obstacles in the way of the truth, even if it requires a bit of... finagling.]

Then as a high-ranking member of Her Majesty's judiciary, I shall myself take full responsibility over your custody. [His voice is raised, the statement directed towards said sailors though he only turns his head halfway towards them.

He doesn't figure they'll know anything meaningful about what authority he may or may not have, anyway, as long as he says it with the right tone of voice. Returning his attention to Ryunosuke:]

Let us not waste any more time, lest the true culprit have the chance to escape.