A U.S. labor group representing more than 1,000 workers at hotels owned by Anbang Insurance Group Co. is asking authorities to force the Chinese firm to disclose its ownership and financing.

The union, Unite Here, filed its complaint with the U.S. National Labor Relations Board after Bloomberg News reported that Anbang faced pressure from the Chinese government to sell overseas assets. Such transactions could negatively impact union members, Unite Here said.

“Our members have a right to know who they’re working for,” said Elliott Mallen, a spokesman for the group. “Unlike more established owners and employers in our industry, Anbang has been extraordinarily secretive about its ownership, which causes us to question the company’s intentions for its hotels.”

A spokesman for Anbang declined to comment. The firm has previously said that it hasn’t received a request to sell overseas assets and “at present has no plans to sell” such holdings. Unite Here has said it has union contracts at Anbang’s Westin St. Francis, Loews Santa Monica and Fairmont Chicago hotels.

Anbang is among prominent Chinese companies that went on global shopping sprees in recent years, drawing attention in the U.S. in 2014 by agreeing to acquire the landmark Waldorf Astoria hotel in Manhattan. Such buying power has prompted public calls for the companies to disclose more about their ownership and finances. In the meantime, Anbang Chairman Wu Xiaohui was detained for questioning in mid-June, while policies fueling the firm’s growth have been all but banned by Chinese regulators.

Anbang’s rise in recent years was helped by sales of lucrative investment products that offered among the highest yields compared with peers. China’s insurance regulator has clamped down in the past year on what it termed “improper innovation” and tightened rules on high-yield, short-term investment policies. Anbang and insurers such as Foresea Life got caught up in the crackdown.

One Anbang product, called Anbang Longevity Sure Win No. 1, boosted the firm’s life insurance premiums almost 40-fold in 2014 by offering yields as high as 5.8 percent. That helped provide fuel for the firm’s more than $10 billion of overseas acquisitions since 2014 and equally ambitious investing in the domestic stock market.