PORTLAND, Ore. - Authorities on Sunday released a photo of a fifth woman they believe could be the key in helping find at least three children who could be at risk for sexual abuse. 

The news came as police in Puyallup, Wash., said tips from people in Portland and Seattle helped them identify two of four women whose pictures were earlier released to the public in the effort to find the children.

Police found the women's pictures along with hundreds of images of child pornography when they arrested a former Portland-area man, 33-year-old Andrew F. Kowalczyk, on suspicion of identity theft at a Puyallup-area motel on Dec. 27.

Police allegedly found the images on Kowalczyk's computer. He is pictured at right.

Investigators believe the children in the photos are possibly abuse victims and the women, who are not suspects, can help find them.

Police did not specify why they believe the fifth woman, pictured at right, is so important to the case.

"We have reason to believe she might be the key in identifying these children," said Puyallup police spokeswoman Lorri Ericson. "Although it is only a partial picture, we are hopeful that some of the viewers may be able to identify her."

Police on Sunday identified two of the children in the photos as possible twins or relatives named Shyann and Lexis. They are believed to be between the ages of 5 and 8, African-American and were once in Portland or western Oregon, police said.

Investigators believe the abuse of the children may have occurred in Seattle, Portland or Los Angeles.

Anyone with information on the women is urged to call police at (253) 841-5421.