An 87-year-old former government official whose car was involved in a fatal crash last month in Tokyo was released from hospital on Saturday before being questioned by police on a voluntary basis, investigators said.

“I’m sorry,” Kozo Iizuka, who sustained broken bones after the crash around noon on April 19 in the capital’s Ikebukuro district, said in a weak voice upon entering Mejiro Police Station.

When he exited the police station, Iizuka was wearing a face mask and sunglasses and using canes to aid walking. He again said “I’m sorry” to reporters gathered at the entrance, but did not answer questions about possible causes of the accident.

While hospitalized, Iizuka also underwent voluntarily questioning by police officers, who seek to charge him with causing death and injury through negligence.

The crash killed a 3-year-old girl and her mother, and injured nine others including Iizuka’s wife, who was in the car with him.

Iizuka has so far claimed that the brake did not work when his car started to accelerate before striking a guardrail, plowing through crossings and hitting a garbage truck.

But police believe he most likely stepped on the accelerator instead of the brake as they have found no technical problems with his car.

The accident has added to concerns about the increasing number of elderly drivers on Japan’s roads as the nation’s population rapidly grays.