The US Securities and Exchange Commission is investigating Tesla for not notifying investors of a fatal crash in May when Autopilot was active, reports The Wall Street Journal.

Tesla previously said that the fatal crash was "not material" information to shareholders after reporters at Fortune accused the company of misleading investors. In an unusual blog post last week, Tesla said that Fortune had mischaracterized an SEC filing from the company and that there was no attempt to mislead shareholders. Now the SEC appears to be investigating Fortune‘s allegations.

The investigation is in the very early stages says the WSJ report, and may not lead to any action by the regulator. An SEC spokesperson had no comment when contacted by The Verge.

"Tesla has not received any communication from the SEC regarding this issue," said a Tesla spokesperson in a statement to The Verge. "Our blog post last week provided the relevant information about this issue."

After the accident but before knowledge of it became public, Tesla held a secondary stock offering that included the sale of several million shares of stock by Elon Musk to cover some of his tax liabilities from exercising his stock options.

Earlier this month, Tesla reported a lower than expected number of vehicle deliveries in the second quarter, while saying it was successfully ramping up production of its vehicles to nearly 2,000 per week.

The National Highway Transportation Safety Administration is also investigating the crash.