Short seller Hindenburg Research said on Tuesday it had a short position in server maker Super Micro Computer, citing evidence of "accounting manipulation".
The company's shares fell about 5 per cent in early trading.
Super Micro did not immediately respond to a request for comment.
Close ties with chip giant Nvidia have allowed Super Micro to quickly roll out servers with AI chips, turning it into one of the biggest winners of the generative artificial intelligence boom.
The company's shares have nearly doubled this year, after more than tripling in 2022, outperforming even Nvidia.
The short seller said it found evidence of undisclosed related party transactions, failure to abide by export controls, among other issues, citing an investigation which included interviews with former senior employees, industry experts and reviews of customers, litigation and corporate records.
Reuters could not independently verify claims in the report.
Hindenburg has been at the forefront of short seller attacks in the past year that have rocked several high-profile companies. Its campaigns led to a rout in shares of Indian conglomerate Adani Group's companies and investment firm Icahn Enterprises.