Hi Romain
Unfortanatly, this is not an isolated case. I have read reports from the ITF magazine and various seafarers missions publications about this problem. It is usually because the crew complain about something, (not being paid, the state of accommodation, and food supplies are the most common ones). It is more common in FoC flag states and there is a campaign against them to force them to clean up their act.
The crew are usually told they can't contact anyone about conditions on board, and many don't. If they do, they, or their familes, are often persecuted, sacked for no reason, and put on a black list which means they can't work on any ship again. This is considered illeagle.
There have also been reports of seafarers work have been returned home, haveing any money in unpaid wages taken of them.
This is just one of the many ships in similar situations in ports around the world.
Regards
Karl
:-)