Despite Apple’s denials, it’s “highly plausible” that secret spy chips could have been planted on the company’s servers, said a former Apple hardware engineer.

Anna-Katrina Shedletsky, who spent nearly six years at Apple helping build several generations of iPod, iPhone and Apple Watch, said spy chips could have been slipped into the design of servers used for Apple’s iCloud services, as alleged in a Bloomberg Businessweek story.

“With my knowledge of hardware design, it’s entirely plausible to me,” she said. “It’s very highly plausible to me, and that’s scary if you think about it.”

Update: Apple and Amazon both issued lengthy statements Thursday concerning the Chinese spy chip allegations. We updated this post to include those statements.

Apple denies that Chinese spy chips infiltrated its iCloud server hardware after claims that motherboards used by Apple, Amazon and dozens of other tech companies contained microchips used for surveillance purposes.

Cupertino insists the story is “wrong and misinformed.” Apple also says Chinese spying had nothing to do with the company’s decision to cut ties with a supplier.