Iranian health officials cast doubt Tuesday on China's reporting of its novel coronavirus toll, saying the figures appear to be too low.

"After the virus spread, it became evident it wasn't as China reported," said Minoo Mohraz, a health ministry official who is also a member of Iran's coronavirus-fighting taskforce. "They're currently retracting many of their articles and their figures and studies have not been very correct," she said, quoted by state news agency IRNA. "With what we know of their scientific studies... their figures are not trustworthy."

Another taskforce official said China's figures were "far from the truth", based on COVID-19's spread and high fatalities worldwide.

Hamid Souri, an epidemiologist, said "distorted data leads to distorted decision-making".

Iran's health ministry spokesman Kianoush Jahanpour came under fire on Sunday after saying China's reporting of its COVID-19 figures was a "bitter joke".

He was slammed on Twitter by the Chinese ambassador to Tehran, Chang Hua, who called on him to "respect realities and the great efforts of the people of China", where the pandemic originated.

Jahanpour later retreated and tweeted that "China's support of Iran in these trying times is unforgettable".

Iran-China relations are usually warm as Beijing is one of Tehran's top trade partners, especially in oil sales. Iran says the virus has killed more than 3,800 and infected over 62,500 in the Islamic republic. But there has been speculation abroad that the real number of deaths and infections could be higher.