Jessica Alba ... a vandal?

Police are investigating after photos posted on a Web site appeared to show the actress putting up posters of a great white shark on property in Oklahoma City.

Police discovered the posters — aimed at raising awareness about the species' declining numbers — glued to a downtown bridge and elsewhere, including a billboard for the United Way charity.

Police Sgt. Gary Knight said Wednesday that investigators have not interviewed Alba, who co-starred in the "Fantastic Four" movies as well as "Sin City" and "Good Luck Chuck." She is in Oklahoma filming "The Killer Inside Me," which co-stars Casey Affleck and Kate Hudson. (A 1976 adaptation of the Jim Thompson novel starred Stacy Keach.)

Telephone messages left with Alba's lawyer and publicist were not returned Wednesday, but the 28-year-old actress released a statement to apologize.

"I got involved in something I should have had no part of," Alba said. "I realize that I should have used better judgment, and I regret not thinking things through before I made a spontaneous and ill-advised decision to let myself get involved with the people behind this campaign. I sincerely apologize to the citizens of Oklahoma City and to the United Way for my involvement in this incident."

Photos that apparently show Alba gluing posters and posing before the defaced billboard were posted to the site of blogger White Mike, but later removed. According to the site, the posters are designed to raise awareness of the dwindling population of great white sharks.

A statement posted to the site Wednesday read: "International pressure is the only way to do it and that starts in Oklahoma, the heartland of America."

An official with the city's Parks and Recreation Department reported the incident to police Monday after spotting the posters and the photos on the Internet. Alba's name is redacted from the police report because she has not been arrested or charged with any crime, Knight said.

United Way of Central Oklahoma President Bob Spinks said Wednesday the group accepts Alba's apology.

"Just as she is passionate about her cause, we are passionate about serving the people of central Oklahoma," Spinks said. "The interesting thing about this is with our fundraising campaign kicking off today, it's been sort of a funny thing that this has happened at this particular point.

"This is probably the best unearned media we've had in a long time."

Under Oklahoma law, maliciously defacing property can be a felony punishable by prison time if the value of the damage exceeds $1,000 or more.

Estimates of the damage are between $500 and $700, said Kristy Yager, a spokeswoman for the city.