Republican Congressman Trent Franks of Glendale is resigning Jan. 31 of next year, he said in a statement to NBC News.
Earlier reports stated the resignation would come because of accusations of "inappropriate behavior" on the part of Franks.
The House Ethics Committee is opening an investigation into whether Franks engaged in sexual harassment, according to the Associated Press.
The statement from Franks says that miscommunication about surrogate parenthood with two women in his office may have led to allegations of sexual harassment.
"Due to my familiarity and experience with the process of surrogacy, I clearly became insensitive as to how the discussion of such an intensely personal topic might affect others," the statement read in part.
"Due to my familiarity and experience with the process of surrogacy, I clearly became insensitive as to how the discussion of such an intensely personal topic might affect others." pic.twitter.com/Pl6xEktqc8— NBC Nightly News with Lester Holt (@NBCNightlyNews) December 7, 2017
Franks' office has not responded to calls from 12 News.
The anti-abortion, family-values congressman has been dogged by rumors of inappropriate behavior for several years, according to several political operatives in Arizona.
The news of his impending resignation comes as a surprise. Franks hasn't been tainted by scandal during his 15 years in Congress.
Under Arizona law, if Franks' announces his resignation immediately, the governor would have to call a primary election within 80 to 90 days, with a general election to fill the seat within 50 to 60 days after the primary.
Franks had planned to run for the U.S. Senate in 2012, and had booked a Phoenix hotel meeting room for the announcement. But it was abruptly canceled just hours before the scheduled start.
This is the 60-year-old Franks' eighth term in Congress, representing a safely Republican West Valley district. He is married and has two children.
Franks is one of the 50 richest members of Congress, with a net worth of $9.85 million, largely from an oil business, according to Roll Call.
Earlier in the day, Democratic Minnesota Sen. Al Franken announced he would resign in the coming weeks after several women accused him of groping and sexually harassing them.