(Reuters) - A congressional investigation found that Wall Street used billions of dollars of American retirement savings and other investments to buy shares in index funds that included several blacklisted Chinese companies, the Wall Street Journal reported on Thursday.

The probe, conducted by a bipartisan House committee empowered to devise strategies for the U.S. to counter China, focused on world's largest asset manager BlackRock ( BLK ) and index provider MSCI ( MSCI ), the report said.

BlackRock ( BLK ) and MSCI ( MSCI ) did not immediately respond to Reuters requests for comment.

Ties between the U.S. and China, the world's two largest economies, have been strained in recent years due to issues including Taiwan, the origins of the COVID-19 pandemic, allegations of spying, human rights issues and trade tariffs.

The House Select Committee on the Chinese Communist Party concluded that through investments in index funds, American financial institutions funneled $6.5 billion last year to some 63 Chinese companies flagged by the U.S., the report said.

The committee could not be immediately reached for a comment.

(Reporting by Mehnaz Yasmin in Bengaluru; Editing by Arun Koyyur)