Tesla Motors (TSLA 3.17%) stock is trading down just over a percent during after-hours trading, after The Wall Street Journal reported that the Securities and Exchange Commission is investigating whether the electric-car maker breached securities laws by not disclosing a fatal crash before its stock offering in May. The crash involved a Tesla vehicle that was driving while its driver-assist Autopilot technology was enabled.

Tesla Autopilot. Image source: Tesla Motors.

The rumored investigation

"The SEC is scrutinizing whether Tesla should have disclosed the accident as a 'material' event," WSJ said, "or a development a reasonable investor would consider important, according to a person familiar with the matter. The SEC's inquiry is in a very early stage and may not lead to any enforcement action by regulators, the person added."

Tesla first disclosed the crash in a June 30 blog post, noting that the National Highway Traffic Safety Administration, or NHTSA, had initiated a "preliminary evaluation into the performance of Autopilot during a recent fatal crash that occurred in a Model S."

The crash was the first known fatality in a Model S that occurred while Autopilot was activated. The crash occurred when a Model S drove under a trailer turning in front of it on a divided highway.

"The high ride height of the trailer combined with its positioning across the road and the extremely rare circumstances of the impact caused the Model S to pass under the trailer, with the bottom of the trailer impacting the windshield of the Model S," Tesla said.

Media coverage of the crash increased when Fortune criticized Tesla's failure to disclose the fatal accident before the stock offering.

But Tesla fired back with a blog post asserting it hadn't even finished its investigation into the crash until "the last week of May," or after the stock offering. The stock offering occurred on May 18 and 19. Further, according to a Tesla SEC filing, underwriters had even already notified Tesla of their intention to exercise their options to purchase shares in conjunction with the offering by May 23.

Further, Tesla emphasized that the crash wasn't material anyway: "Given the fact that the 'better-than-human' threshold had been crossed and robustly validated internally, news of a statistical inevitability did not materially change any statements previously made about the Autopilot system, its capabilities, or net impact on roadway safety."

And Tesla contends that muted market response to the June 30 news also confirms "that not only did our investors know better, but that our own internal assessment of the performance and risk profile of Autopilot were in line with market expectations."

Should investors be concerned?

Model S. Image source: Tesla Motors.

If the SEC does open an investigation and eventually determines there was a securities-law breach, there are likely to be financial repercussions for the company. But it's worth noting that Tesla hasn't yet heard directly from the SEC about an investigation.

"Tesla has not received any communication from the SEC regarding this issue," a Tesla spokesperson confirmed with The Motley Fool. "Our blog post last week provided the relevant information about this issue."

Further, investors should keep in mind that even if this report is right about an SEC investigation, the WSJ said the investigation is in "a very early stage" and may not lead to any penalty.

Notably, considering that the stock is down just 1% in after-hours trading following WSJ's report, investors don't seem to be too concerned about the news.