"Half of all black children are aborted", Franks infamously said in 2010.
"If this turns out to be true, there won't be that many people who are surprised", the Arizona Republican said, according to the report.
"I'll let the statement speak for itself", the Arizona Republican told reporters as he was leaving the House floor Thursday evening after voting to avert a government shutdown and fund the government for an additional two weeks.
Franks is also a member of the House Freedom Caucus, a hard-right faction that has often clashed with Republican leaders. Biggs said he would not comment until Franks announced his plans. It did not elaborate why Franks has chosen to resign.
Franks was first elected in 2002 and considered a 2012 Senate bid before deciding against it.
Franks is a congressman from Arizona's 8th district. Franks won an eighth term last fall by 37 points.
The AP reported on Franks' resignation Thursday afternoon, based on its sources.
The governor is required to establish the date of the primary election within 72 hours of the seat being officially vacated.