A watchdog group has asked the IRS to investigate the conservative Christian group Focus on the Family.
The watchdog group called Citizens Project wants to know whether Focus broke the law by trying to sway voters in the presidential election.
The group is taking issue with a November article in a magazine printed by Focus that compared presidential candidates and their positions on abortion, stem-cell research and same-sex marriage.
As a nonprofit organization, Focus on the Family is forbidden to endorse political candidates or parties.
Focus officials say the article is not illegal because it was written under the guise of its separate lobbying arm, Focus on the Family Action.