The conclusion follows previous denials of a Bloomberg Businessweek magazine report that said Chinese intelligence services inserted malicious components in the company's server motherboards during the manufacturing process.
In a letter to customers posted to his company's website, Super Micro Chief Executive Officer Charles Liang said that "after thorough examination and a range of functional tests, the investigations firm found absolutely no evidence of malicious hardware on our motherboards."
The company said the third-party investigations firm had tested "a representative sample" of its motherboards, including the specific type of components which were the focus of the Businessweek story and which had been purchased by a number of large technology companies mentioned in that article, as well as more recently manufactured examples.
The letter reiterates that no government agency or customer has ever contacted the company about malicious hardware.
Bloomberg Businessweek has previously said that it stands by its story.
