PORTLAND, Ore. -- Police in Portland are investigating an ad posted on the popular Web site Craigslist featuring a baby for sale for $1,000.

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VIDEO: Ad On Craigslist For Baby

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The ad shows a baby covered in food or mud being held by an adult.

Text with the ad reads, "We are out of tweak and we will sell this baby for a thousand dollars." Tweak is another word for methamphetamine, Local 6 reported.

Lt. Dave Okada said detectives are trying to track down whoever posted the message.

"Whether it's a joke or truly serious, it is not funny," Okada said.

Nicholas Dunbar and his friends said they spotted the advertisement on Craigslist under the Salem-area "rants and raves" section and immediately called police.

Officers said if the ad is real, the baby is in danger.

Watch Local 6 News for more on this story.