(CNN)Donald Trump's nominee to head the Treasury department, Steven Mnuchin, is registered to vote in two states, a CNN KFile review of paperwork obtained through open records requests in New York and California show.

While it is illegal to cast ballots in multiple states, it is not illegal to be registered in two states at the same time. In a tweet Wednesday, the president called for an investigation into voter fraud, including whether citizens are registered to vote in two states.

"I will be asking for a major investigation into VOTER FRAUD, including those registered to vote in two states, those who are illegal and even, those registered to vote who are dead (and many for a long time). Depending on results, we will strengthen up voting procedure," the president wrote in a pair of consecutive tweets.

CNN's KFile has also confirmed that before Wednesday morning, Steve Bannon, Trump's chief strategist and senior counselor, was registered to vote in both New York City as well as in Sarasota County, Florida. Since then, the supervisor of elections for Sarasota County said that Bannon was removed from the voting rolls on Wednesday after his office received confirmation from the city of New York that Bannon was registered to vote there too. Bannon's registration status was first reported by the Sarasota Herald-Tribune.