WASHINGTON – The Pentagon is investigating an Internet porn site that is publishing nude photos of what it claims are three female GIs in Iraq, The Post has learned.

An inquiry began last Friday after Army personnel officials were informed that several provocative photos of the three women were posted on a Web site that specializes in “amateur pornography,” and that the women were identified as soldiers serving in Iraq.

An Army spokesman said officials have not been able to confirm that the women on the Web site are actually GIs. He added that until that can be established, all other questions on the issue are “hypothetical.”

But one of the women, whose name and photos were published by the porn site, was also featured on a Pentagon public-relations Web site while she was on an R&R trip to Kuwait, The Post discovered.

One of the others was also identified on the porn site; the third was not.

The name of the Web site cannot be published because it contains an obscenity in its name.

But Chris Wilson of Lakeland, Fla., who runs the site, says it has 31,000 registered subscribers.

“We seem to be pretty popular with soldiers overseas. At least 30 percent of my registered users are soldiers,” Wilson said.

The women involved may also be victims. Wilson admitted that the photos on his Web site appear to have become public without their consent or knowledge.

He said one set of photographs was sent by a lonely female GI to her boyfriend or husband back home over a computer that is shared by other soldiers at their base in Iraq.