China’s military has launched an inquiry into corruption linked to procuring hardware going back more than five years, urging the public to step forward with tips on wrongdoing.

In an unusual move, the military’s Equipment Development Department listed eight issues it was looking into, including “leaking information on projects and army units” and helping certain companies secure bids.

The inquiry will focus on experts who reviewed the tender process, the department said in a statement on social media on Wednesday night, and was needed “to create a good environment for procurement bidding and evaluation” and to “rectify violations of rules and discipline.”

The investigation is a sign that Chinese leader Xi Jinping’s nearly decade-long drive to clean up the People’s Liberation Army is incomplete. Back in 2014, China started launching probes into some of its top current and retired generals, including two who had sat on the body that runs the PLA, the Central Military Commission.

See: Xi Urges China Military to Strengthen Communist Party Leadership

That has coincided with Xi pushing China’s military to to modernize, including by stepping up innovation. Under his watch, China set a goal of fielding “a modern military” by 2027. The US’s top uniformed officer, General Mark Milley, has told Congress that Xi wanted the ability to overrun Taiwan by 2027.

Xi — chair of the Central Military Commission — called for strengthening governance of the armed forces at a meeting of the Communist Party’s 24-member Politburo on Monday, citing the need to improve oversight of spending. That came just days after he called on the party to command “absolute leadership over the military.”

The latest announcement said that the military is investigating problems going back to October 2017, without saying why that date was significant. China’s current defense minister, Li Shangfu, headed the equipment department from September 2017 to 2022, though there is no sign that he is suspected of wrongdoing.