A wartime myth about Greek merchant ships

Is there evidence that Greek shipowners bribed U-boat commanders to spare marked ships?

No evidence is identified for it, and the story is treated as an unsupported wartime myth.

No supporting evidence is identified for the story, which belongs among the many naval myths that circulate without solid documentation. The alleged lighting and markings would also have been conspicuous in a war where merchant ships normally tried not to advertise themselves at night. Wartime authorities watched for collusion of this kind, yet no substantiating record is identified. The wider political context also counts against it. Greek forces had fought the Italian invasion fiercely before Germany intervened, giving Greek crews and shipowners strong reasons to resist rather than assist the Axis.