The 46,200-dwt Nobel (built 1997) had a sordid past. Before it made headlines last month for transferring cargo to a Maersk Tankers ship, it participated in a series of ship-to-ship transfers over several months, according to maritime intelligence firm Windward.

The ship had allegedly engaged in a number of activities that could have raised red flags too, such as hopping between flag registries and being owned by a low-profile owner based in a non-traditional jurisdiction for shipping companies.