Iran has sent at least 11.7 million barrels of crude oil through the waterway since the war began, all of which were headed to China: TankerTrackers.

Many ships have "gone dark" after Tehran threatened to attack any vessel attempting to pass through the waterway.

Iran has also resumed loading tankers at the Jask oil and gas terminal along the Gulf of Oman, south of the Strait of Hormuz, which could add additional capacity to its crude shipments.

Iran has continued to send large amounts of crude oil via the Strait of Hormuz to China even as the war between U.S.-Israel and Iran has jeopardized broader supplies through the critical waterway.

Iran has sent at least 11.7 million barrels of crude oil through the Strait of Hormuz since the war began on Feb. 28, all of which were headed to China, Samir Madani, co-founder of TankerTrackers, told CNBC on Tuesday.

The firm monitors vessel movements with satellite imagery, allowing it to capture vessels that would otherwise go undetected if their tracking systems are switched off. Many vessels have "gone dark" after Tehran threatened to attack any vessel attempting to pass through the waterway.

Shipping intelligence data provider Kpler estimates around 12 million barrels of crude oil to have passed through the strait since the war started. "Given that China has been the primary buyer of Iranian crude in recent years, a significant share of these barrels could ultimately head there," said Nhway Khin Soe, crude analyst at Kpler, adding that confirming the final destination for these vessels had become increasingly challenging.