HONG KONG (AP) — Chinese tech stocks Lenovo Group and ZTE Corp. have tumbled in Hong Kong following a news report Chinese spies might have used chips supplied by another company to hack into U.S. computer systems.

Lenovo shares fell 20 percent on Friday but recovered some of that to be off 15 percent at mid-afternoon. ZTE was off 11 percent.

Bloomberg News cited unidentified U.S. officials as saying Chinese spies inserted malicious chips into equipment supplied by Super Micro Computer Inc. to American companies and government agencies.

Lenovo said in a statement Super Micro “is not a supplier to Lenovo in any capacity.”

Super Micro denied its products contained malicious chips.