In a rare step, Chinese smartphone maker Xiaomi has issued a statement against market research firms for reporting wrong shipment numbers for its devices in the first quarter of 2019.

Lei Jun, Chairman of Xiaomi Corporation, said that several media publications quoted some information from certain market research institutions about their estimated shipment of smartphones in the first quarter of 2019.

"The information is inaccurate and unfair, and deviates from our actual performance in terms of shipment of smartphones," Jun wrote in a letter on Friday, without mentioning the name of the market research firms.

"Our shipment of smartphones in the first quarter of 2019 exceeded 27.5 million," he added.

International Data Corporation (IDC) had reported that Xiaomi shipped 25 million units in Q1 2019.

"Xiaomi also experienced a decline in 1Q19 with volumes of 25 million, which was down 10.2 per cent year over year," the IDC reported.

"India was the only country in Asia/Pacific where Xiaomi grew its shipments during the quarter," it added.

Another market research firm Canalys also issued a statement, saying its own estimates for Xiaomi at 27.8 million units were close to the figure the Chinese company has mentioned.

Canalys said it "wants to make it absolutely clear that it was not the company responsible for the inaccurate data and that its reputation remains unblemished".