Coastguards have detained an offshore supply vessel at Aberdeen harbour amid crew welfare concerns.
Ben Nevis will not be allowed to leave the port until an inspection is completed.
The Maritime and Coastguard Agency said it had taken action as the Port State Control Authority for the UK.
The ship's operator Global Offshore Services BV has been contacted for comment. The RMT union welcomed an investigation being carried out.
Ben Nevis was detained on Monday to allow a full inspection of the ship related to the Maritime Labour Convention.
Fraser Heasley, the MCA's assistant director of survey and inspection, said: "We will always take reports around crew welfare seriously.
"We have used our powers to carry out this detention so that we can investigate more fully."