General Motors could be facing another fine by the U.S. government for delaying a recall on certain Chevrolet Impalas.

According to NBC 25, a U.S. House subcommittee produced a nine-year-old email this week from a GM employee warning about a potential safety problem on the 2006 Impalas. GM didn't issue a recall on the Impalas until earlier this week. Federal law says automakers must notify the government within five days of determining whether a safety issue exists.

GM has already been fined $35 million for taking too long to issue a recall for some of its small cars with an ignition switch problem. It could face another fine for the Impala case.