Iran’s exports have shrunk since the United States withdrew from a nuclear deal with Iran and reimposed sanctions on its energy and banking sectors in 2018. But data from TankerTrackers and two other tracking firms indicated exports are rising.

“Exports are way up right now. We are seeing close to 1.5 million bpd in both crude and condensate so far this month,” Samir Madani, cofounder of TankerTrackers, told Reuters. “These are levels we haven’t seen in a year and a half.”

The amount was twice that of August, TankerTrackers data showed, and around 11% of it was ultra-light crude, known as condensate.

Data from TankerTrackers, which tracks shipments and oil storage, showed almost half of Iranian exports were picked up by foreign vessels via ship-to-ship transfers.

The two other firms, asking not to be named, also see an increase in September although not to the same extent.

One of them said it was seeing an increase of at least 100,000 bpd in September – a sizeable volume compared to a low point in May when Iran’s crude exports fell to 100,000 to 200,000 barrels per day (bpd) from 2.7 million bpd in May 2018.

Iran’s Oil Minister Bijan Zanganeh defended last week his efforts to boost exports of crude despite U.S. sanctions and said oil documents were forged to hide the origin of Iranian cargoes.

“What we export is not under Iran’s name. The documents are changed over and over, as well as specifications,” he said in Parliament.

Refinitiv Eikon, which shows Iranian exports of crude and condensate at around 383,000 bpd in August, has reported no crude and condensate exports so far in September.

With the sanctions reducing sales, Iran has been storing unsold oil in tankers at sea. While onshore storage has increased, the volume in floating storage has fallen in 2020, suggesting Iran has found end-users for some of the oil.

The floating storage volume has fallen by about 20 million barrels, separate data provided by OilX and Kpler showed.

Iranian Foreign Minister Mohammad Javad Zarif has strongly criticized US sanctions against the Islamic Republic’s economic infrastructure as well as food and medical business as “economic terrorism”.