Real-time readings of PM2.5 - airborne particles measuring less than 2.5 microns in diameter - released on many mobiles are not correct because of faulty software, an official of the Beijing Municipal Environmental Protection Bureau said on Wednesday, Beijing Youth Daily reported.

Yu Jianhua, head of the atmosphere department of the bureau, said some mobile phone software is using the wrong method of calculations and formulas.

A thorough air quality monitoring network has been built up in Beijing and the government has also developed mobile software to release real-time air quality index, Yu said.

"I suggest downloading the professional software from the official website of Beijing Municipal Environmental Protection Bureau," Yu said. "The air quality report is the most authoritative and accurate."