LONDON (Reuters) - Iran denied on Wednesday reports that its exports of crude oil to Chile’s state energy company ENAP might have been a possible source of noxious fumes that caused hundreds of people to seek hospital treatment in August.

A total of 508 people, most of them children, sought treatment in Quintero and nearby Puchuncavi in August after residents reported a strong smell in the air. Chilean law enforcement officials are investigating Iranian crude oil as a possible source of the odour. [nL1N1YM1TA]

On Wednesday, the National Iranian Oil Company (NIOC) denied any links between its crude exports to Chile and the noxious fumes. NIOC said international inspectors monitor the flow, loading and export of its oil and issue certificates which allow continuation of the exports.

“Iran’s export terminals are equipped with state-of-the-art laboratories and devices for checking and measuring the quality and amount of the oil, and the quality of the export oil is always being examined at different times of the day,” NIOC said in a statement published by the oil ministry news agency SHANA.

Last month the United States reimposed sanctions against Iran’s oil sector after pulling out of world powers’ 2015 nuclear deal with Iran, saying Tehran was continuing to develop ballistic missiles and interfere in Middle Eastern conflicts.