The job-hopping of a veteran rocket scientist has revealed the plight State-run research institutes face in retaining high-caliber talent.

Xi'an Aerospace Propulsion Institute, an agency under the China Aerospace Science and Technology Corporation (CASC), made an announcement on Thursday following heated public discussion over a rocket engine scientist who quit the institute to join a private company, where he would allegedly be paid much higher.

The text of the announcement claimed Zhang Xiaoping, a designer of rocket engine propellant, has violated the confidentiality rule which bans staffers holding classified information concerning national security from leaving the institute within a period of two years after resignation.

Zhang applied for resignation in March, and despite the institute's efforts to retain him, he left the institute without its permission.

The institute later appealed to the city's labor dispute arbitration authority to ask Zhang to abide by the confidentiality rule by working for a non-classified position for two years before quitting.

Zhang joined the institute in 1994 and worked on designs for cryogenic propellant of rocket engines since 2015, according to the announcement.

The statement was made after a widely-circulated online article said Zhang had quit his job at the institute for higher payment at a private company, lamenting poor incomes some high-level technicians receive at State-owned research institutes.

The article enclosed a document the institute filed to the city's labor dispute arbitration authority, which shows Zhang played a key role in a research project related to the country's manned lunar landing program, and his quitting has left a tremendous impact on the project.

The document alleged Zhang earned only 120,000 yuan a year ($17,450), much less than the 1 million he could make with the new employer.