Top Republican financial officers from 21 states have urged the Securities and Exchange Commission to determine if Chinese companies on US stock exchanges should be delisted for failing to protect American investors.

The officers on Tuesday asked SEC chair Paul Atkins to investigate the companies because of Chinese policies that “create an environment of opaqueness that is antithetical” to the reporting requirements of US laws.

“China’s actions create an environment ripe for fraud and abuse, increasing the likelihood that China-based US-listed companies will violate the disclosure, auditing or anti-fraud provisions of the Securities Exchange Act,” the officers from states including Pennsylvania, South Carolina and Arizona said in the letter obtained by the Financial Times.