SHANGHAI (Reuters) - An Australian currency brokerage said three staff members in Shanghai, who were being held against their will by a group of investors that intruded into its offices last week, had been released and were now helping with a local police investigation.

Sydney-headquartered brokerage, Union Standard Group Forex (USGFX), last week said up to 50 investors had come into its central Shanghai offices on Wednesday in protest against losses made on currency trades.

After many attempts to negotiate, those being held were released on July 24, the company said in an e-mailed statement on Tuesday. “The three USGFX staff members have finally been relocated to a police station to help proceed with the investigation,” it added.

A company spokesman said among the three staff members was a USGFX vice-general manager.

USGFX has said that investors who had used a third-party agent to trade currencies on its platform were blaming it for heavy losses of $2.6 million made on Australia-to-U.S. dollar trades and wanted compensation.

Reuters was unable to reach the intruders for a comment. The Shanghai police, which confirmed to Reuters earlier that they were looking into the case, did not respond to calls on Tuesday.

The incident is the latest sign of flaring tension in China’s financial system, where many investors feel duped after suffering losses from riskier investments in wealth management products.

Angry Chinese investors have taken matters into their own hands before. In 2015, a Chinese investor stabbed the chief executive of a struggling Beijing-based asset management company after losing his investment.