BEIJING — U.S. investments in around 50 blacklisted Chinese companies have drawn the attention of the U.S. House of Representatives Select Committee on the Chinese Communist Party.

The committee on Tuesday announced it sent separate letters to and asking for more information about the firms' facilitation of U.S. investments into those Chinese companies.

The Chinese companies were blacklisted over claims of supporting China's military or alleged human rights abuses, the committee said. It noted the initial review did not include one of the largest blacklists, the U.S. Department of Commerce's Entity List.

"The true scale is likely much larger," the letters said.

MSCI said in a statement it is reviewing the request for information, and that it doesn't "facilitate" investments in any country. "MSCI indexes measure the performance of equity markets available to international investors, and comply with all applicable US laws," the indexing giant said.

BlackRock said most of its clients' investments in China are through index funds. "We are one of 16 asset managers currently offering US index funds investing in Chinese companies," the asset management giant said, noting it also offers clients strategies to exclude China from portfolios.

Here's the full list of names, which are primarily state-owned companies:

The U.S. House committee estimated that five BlackRock funds have invested more than $429 million into the blacklisted names. Those companies also accounted for nearly 5% of the MSCI China A Index's value as of March 1, the committee said.

The request for information comes as the U.S. has increased its scrutiny of financial ties with China.

Last week, the U.S. Senate overwhelmingly when investing in advanced Chinese technology on national security concerns. An earlier version of the legislation had called for investment restrictions.

President Joe Biden has long been expected to issue an executive order that would restrict U.S. investment in high-end Chinese tech. No action has yet been announced.

Last month, the House committee said it over their investments into Chinese artificial intelligence, semiconductor and quantum computing companies.

The committee cited allegations that China was using such technologies for military development or perpetuation of human rights abuses.

Beijing has denied such abuses, and published in the United States."