Tesla said the Justice Department requested documents last month regarding CEO Elon Musk's Aug. 7 tweets about taking the company private.

The shares sank by as much as 7.1 percent earlier Tuesday after news broke that federal prosecutors have opened a criminal probe looking at his comments. Musk tweeted on Aug. 7 that he had secured funding at $420 a share to take the electric car maker private, sending the stock soaring 11 percent, near an all-time high that day to $387.46. All of those gains — and then some — have since been erased.

Tesla acknowledged that the agency asked for documents from the company after Musk's now infamous tweet in a statement released Tuesday:

"Last month, following Elon's announcement that he was considering taking the company private, Tesla received a voluntary request for documents from the DOJ and has been cooperative in responding to it. We have not received a subpoena, a request for testimony, or any other formal process. We respect the DOJ's desire to get information about this and believe that the matter should be quickly resolved as they review the information they have received."

Bloomberg said the Justice Department is running the criminal investigation in tandem with a civil fraud probe by the Securities and Exchange Commission of Musk's comments. It cited two people familiar with the matter.

In addition, The New York Times reported that the SEC has sent subpoenas to Goldman Sachs and Silver Lake, both of which Tesla engaged to help it evaluate the take-private proposal.

Tesla's value has fallen by almost a third since his initial tweet, wiping away nearly $18 billion in market capitalization. The stock rebounded somewhat from its intraday low Tuesday but was still down by about 3 percent at $285.92 a share.