HOUSTON (AP) — Two activist groups say they sent an email to more than 71,000 Shell Oil employees that pretended to be from a fake company division and provided information about a U.S. Supreme Court case involving Shell.

The groups, People Against Legalizing Murder and the Yes Lab, said Tuesday that a day earlier they sent the email from Shell's "Grassroots Employee Empowerment Division," which doesn't exist.

The email detailed a lawsuit against Shell's parent company, Royal Dutch Shell (RDS.A), that was argued Monday before the high court. The suit claims the company was complicit in murder and other abuses committed by the Nigerian government.

Kayla Macke, a Shell spokeswoman in Houston, confirmed employees got the email and were told it was fake.

The company is investigating how the email was sent.