The rogue CEO of chip designer Arm's Chinese unit has refused to leave his role after being fired last week, for the second time.

Allen Wu was also fired in 2020 amid claims of conflicts of interest, but simply did not leave, essentially operating the division as an independent company.

Arm owner SoftBank is keen to resolve the issue, as it prepares to take the company public following the collapse of Nvidia's $60 billion attempted acquisition.

Back in 2020, Arm said that the CEO of its Chinese joint venture was to blame for "serious irregularities, including failing to disclose conflicts of interest and violations of the employee handbook."

The company and its board claimed that Wu operated his own investment fund, Alphatecture, raising $100m from companies that had relationships with Arm China, and investing in companies that would benefit from cheaper licenses from Arm.

Wu hit back, saying that Arm knew about the fund and that it was all above board. He then fired his replacement CEO, Phil Tang, "due to serious irregularities." The Arm board reinstated Tang and two others fired by Wu. The three executives are now being sued by Arm China.

While the board voted to remove Wu, the CEO holds the physical papers that give him control over the business. In the meantime, the division went rogue, and is pursuing its own R&D agenda, and exploring technologies outside of the core Arm universe.

In late April, it appeared that SoftBank had been proved victorious, saying that it had once again fired Wu and this time replaced him with Liu Renchen and Eric Chen.

The company claimed it had followed Chinese law, and said that it had the backing of both the Chinese board and Chinese authorities.

But Allen Wu has refused to step down, and those loyal to him still control Arm China websites and social media. In a post on the regional division's website, purportedly signed by 430 employees, the company says it will remain loyal to Wu and that there are "major legal flaws" with the attempted firing.