A sizeable oil slick developed in waters where tankers were damaged off the United Arab Emirates on 12 May.
Finnish company Iceye says one of its radar satellites detected a long trail leading from the Saudi-flagged vessel Amjad two days later.
The crude oil tanker and three other ships suffered damage while anchored outside the port of Fujairah.
No-one has yet said they were behind the incidents. Nor is it clear precisely what happened.
US investigators reportedly believe Iran or groups it supports used explosives to damage the ships – but no evidence has emerged to show that Iran was involved.