General Motors said Monday it will pay at least $1 million in compensation to the families of each person killed in accidents apparently caused by defective ignition switches in its cars.

GM has so far publicly acknowledged 13 deaths linked to the ignition switch defect, but federal safety officials suggest the toll could be higher.

The top US automaker is under investigation for failing to recall the problem cars for more than a decade, even after some in the company were aware of the defect.

GM began recalling 2.6 million older model cars only in February.

Kenneth Feinberg, the prominent lawyer GM appointed to head the compensation fund, announced Monday that claims will be taken from August 1 through December 31.

“There is no ceiling on the aggregate dollars,” he told a press conference.

For each eligible death claim, in addition to the $1 million for the victim, $300,000 will be awarded for the surviving spouse and another $300,000 for each of the victim’s surviving dependents.

Financial and medical treatment compensation will also be offered for those with eligible physical injury claims from an accident.

People who were killed or injured prior to GM’s government-backed bankruptcy reorganization can file claims with the “new” GM.

“For accidents, the GM bankruptcy is no bar to filing a claim on this program,” Feinberg said.

GM is reportedly facing a federal criminal probe and is under congressional investigation for not having recalled the cars years ago.

The company says it knows of 13 deaths and 54 accidents in which air bags did not deploy, possibly due to the ignition problem.

The US auto safety regulator, the National Highway Traffic Safety Administration, said it thinks the death toll could be higher.

And the independent Center for Auto Safety says it has counted more than 300 deaths linked to air bag non-deployment in the GM cars covered by the ignition recall, though it has not linked that problem to ignition shutdowns.

Since the first recall in February, GM has scoured its safety files and initiated recalls of more than 27 million cars, in an effort to ward off fresh scandals and begin rebuilding the company’s battered reputation.