First reported by Bloomberg on Friday, the Liberian-flagged vessel Vivit Africa LNG loaded its cargo at Cameron LNG’s terminal in Louisiana in late-August and crossed the Atlantic only to abandon its planned European delivery after a sudden system malfunction forced the vessel to idle off the coast of Italy for several days. On Wednesday, the 299-meter LNG tanker altered course to sail west towards Algeciras, Spain, without delivering its cargo to the Italian buyer, according to Bloomberg.

Near the same time, the FBI and the U.S. Coast Guard last week confirmed they boarded two inbound foreign-flagged commercial ships in the Gulf of America to “ensure integrity of the vessel’s operational and information technology systems” following indications that the computer networks of both were compromised.

Reports in shipping industry publications, including The Maritime Executive and Safety4Sea, indicate that hackers gained temporary control of the steam pressure and safety valve systems during Vivit Africa LNG’s transit of the Strait of Gibraltar. According to Marine Insight, as the ship neared its destination of Rovigo, Italy, the hack compromised the automated tank pressure control systems and disrupted the vessel’s vital boil-off gas management cycle, which could have resulted in catastrophic failures.

Federal agents last week confirmed the late-August boarding of another Liberia-flagged vessel, the crude oil supertanker VL Prosperity, in seas near Galveston, Texas. After traveling through the Strait of Gibraltar in early August the crew of the VL Prosperity experienced a 30-hour communications blackout and engine-room systems malfunction.