Paparazzi gathered in Namibia are pacing the floor like anxious fathers in a maternity ward.

With tabloids predicting the imminent arrival of the most famous celebrity baby of the year, Hollywood stars Angelina Jolie and Brad Pitt remained almost invisible in their remote Namibian resort, ducking reporters intent on getting a career-making scoop.

Despite a widely reported due date of May 18, there was little sign on Thursday the baby was about to make its appearance — leaving gossip hounds panting for news.

A local newspaper on Thursday quoted sources saying Jolie was to give birth within the next two days, possibly opting for a home birth with a special aircraft on standby.

"Jolie... is expected to go into labor in the next 48 hours," the Namibian said under the banner headline "Jolie-Pitt baby expected shortly."

There are three private hospitals in the two closest towns of Walvis Bay and Swakopmund.

But other baby-watchers have concluded the real due date could still be weeks away, making for an even longer wait for what one New York magazine dubbed the most eagerly anticipated birth since Jesus.