The NBC report, based on data from TankerTrackers.com, a company that tracks oil exports, brought up the case of the Indian tanker Gissel. The tanker left Pakistan in April and seemed to begin a standard journey up the Persian Gulf. Tracking data then showed the ship making a U-turn near the Straits of Hormuz and coming to a stop in the Gulf of Oman.
However, satellite images showed that the ship was not at the marked location. TankerTrackers used satellite imagery to find Gissel off the coast of Lavan Island, over 100 miles away from the marked location.
While off the coast of Lavan Island, the Gissel met up with an Iranian oil tanker, which transferred an estimated one million barrels of crude oil to the Gissel. The Gissel continued on to deliver the oil to China.
TankerTrackers has found that similar maneuvers have been used by Iran many times to transfer and export millions of barrels of oils and bypass US sanctions.
While a June report by Chinese customs says that no Iranian oil was imported that month, a source told Radio Farda that the oil was delivered as Indonesian oil.
A recent congressional report estimated that Iranian oil exports had dropped 90% since 2018, falling from 2.5 million barrels a day to 227,000 barrels a day, according to NBC News. TankerTrackers findings show that exports have instead fallen by about 76%.
The Islamic Republic's crude production has halved to around 2 million barrels per day (bpd), but Iran has stated that it intends to continue to develop its oil industry despite sanctions.
Reuters contributed to this report.