Reuters had previously reported the FBI would launch an investigation into the hack.

The FBI inquiry is now one of multiple investigations into the incident, which has drawn scrutiny from a number of officials. New York Governor Andrew Cuomo also announced an investigation into the attack. Cuomo said the hack was “deeply troubling and raises concerns about the cybersecurity of our communications systems.”

Several members of Congress have also signaled their concern. Missouri Senator Josh Hawley sent a pointed letter to Twitter CEO Jack Dorsey in the hours immediately after the attack, and a number of House Republicans have said Dorsey should brief Congress on the company’s security practices and the events leading up to the hack.

Twitter has so far provided relatively few details about how the hacks occurred. The company has blamed it on a “social engineering attack” that targeted employees with access to internal tools that could grant account access. The company hasn’t directly commented on speculation that an employee may have been paid to aid in the attack. Twitter also said it doesn’t believe users’ passwords were compromised.

Developing..