A leading marine lawyer has warned of increased congestion and collision risk as ships try to avoid Iranian waters.

Reports have claimed a number of vessels have turned off transponders while transiting the Strait of Hormuz, as well as slightly altering routes, following the seizure of Stena's MR Stena Impero by Iranian forces.

Reed Smith partner Richard Gunn, a master mariner, said: "Avoiding Iran’s waters will present its own problems.