State-owned newspaper IRAN reports the woman had spying equipment hidden on her body when customs authorities detained her in a border town 370 miles northwest of the capital Tehran.
The daily says she arrived from neighboring Armenia without a visa. It did not say when she was allegedly detained.
While the report of an arrested American along Iran's Armenian border was mentioned on several other official news websites, it has not been discussed on Iran's state controlled television networks or any of the larger official newspapers or news outlets.
A CBS News producer in Tehran says one website, AFKAR NEWS, has run a photo of the woman, identified as Hal Liyan, but there is no way to confirm its authenticity.
The Iranian Foreign Ministry would not comment on the matter when contacted Thursday by CBS News.
If the reports are valid, the woman would be the fourth American Iran has arrested and accused of spying in less than two years.
In July 2009, Iranwho were initially accused of crossing the border illegally from northern Iraq and later accused of spying.
The U.S. says the three are innocent hikers. Their families have said if they crossed the border at all, it was inadvertent.
One of the three was released in September on compassionate grounds.