Takata Corp. said Wednesday it was fully cooperating with the investigation of the accident, in which a woman in the front passenger seat of a Nissan X-Trail sport-utility vehicle was injured.
Nissan said it's also cooperating with the investigation, but declined comment, noting the case is still under investigation.
Kyodo News service reported, citing anonymous investigative sources, the woman was injured in October 2015, in Shizuoka Prefecture, central Japan, and metal fragments that injured her were later found to be from the inflator.
Police are looking into the complaint, filed on May 30, on suspicion of professional negligence resulting in injury, Kyodo said. Shizuoka police declined comment.
Takata has gradually expanded its recalls over defective inflators that can explode with too much force, sending shrapnel spewing.
The recalls, as of the latest count, are likely to tally more than 100 million inflators globally. Faulty air bags are responsible for 11 deaths and more than 100 injuries worldwide. Two more deaths are under investigation in Malaysia.
The recalls involve almost every major automaker, including Honda Motor Co., Toyota Motor Corp., Ford Motor Co. and BMW, as well as Nissan.
Takata uses the chemical ammonium nitrate to create a small explosion that inflates air bags in a crash. But the chemical can deteriorate over time when exposed to high heat and humidity and burn faster than it is designed to.