A federal grand jury announced Thursday it has subpoenaed documents from General Motors Co. (NYSE:GM) regarding its recall of 2.6 million cars linked to a faulty ignition switch, the Wall Street Journal reported.

GM says the switch is linked to at least 13 deaths in Chevrolet Cobalts and Saturn Ions. The federal grand jury wants to know why it took more than a decade for the automaker to issue a vehicle safety recall despite evidence that people inside the company were aware of the problem.

GM had announced previously that it was the target of queries from all three branches of the federal government for its handling of a fatal ignition switch defect in some of its cars dating as far back as 2002. A report from Anton Valukas, the former federal prosecutor hired by GM to investigate why it took so long to own up to the problem, said he found no evidence of a cover-up, but that there was no evidence anyone “deliberately withheld” information about safety issues. 

The world’s third-largest automaker has issued 44 recalls so far this year covering 20 million vehicles worldwide. On Tuesday it told dealers to stop selling its Chevrolet Cruze compact sedan for faulty airbags that are plaguing other automakers too. So far the company expects to spend at least $1.3 billion to repair flaws it has identified in its vehicles.

GM had disclosed in its first-quarter earnings report on April 24 that it was “subject of various inquiries, investigations, subpoenas and requests for information from the U.S. Attorney’s Office for the Southern District of New York, Congress, NHTSA, the SEC, and a state attorney general in connection with our recent recalls.”