Updated

Hackers briefly hijacked the "Sesame Street" YouTube page and replaced Bert, Ernie and Big Bird with hardcore porn, E! Online reported Monday.

For about 20 minutes Sunday, users who clicked on links to watch scenes from the long-running PBS kids' show were instead confronted with x-rated videos, the company said on its video page.

The hackers added the text "It's where porn lives" underneath the page's "Sesame Street" logo and wrote in a video description, "Who doesn't love porn kids? Right! Everyone loves it."

"We apologize for any inconvenience our audience may have experienced yesterday on our Sesame Street YouTube channel," reads a statement on the site. "Our channel was temporarily compromised, but we have since restored our original line-up of the best classic Sesame Street video clips featuring Cookie Monster, Big Bird, Grover, Oscar the Grouch, and the rest of the fuzzy, feathered, and googly-eyed friends you remember from childhood."

YouTube briefly removed the entire channel immediately after the incident, which most likely a malicious prank, experts told FoxNews.com.

"It most probably was a prank -- but what prankster would think it's okay to expose children to this? That's pretty horrifying," said Ira Victor, director of the digital forensics practice with Data Clone Labs and a member of the High Technology Crime Investigation Association.

A YouTube user with the handle "MrEdxwx " denied he had taken part in the hacking despite his username appearing on the hacked channel before it was taken down.

"I did not hack 'Sesame Street,'" he wrote on his own channel, which is dedicated to video games. "I work hard to make quality gameplay videos, and most important I respect the community guidelines."

so who did?

Precisely how Sesame Street's YouTube channel was hacked is presently a mystery, explained Graham Cluely, Sophos senior technology consultant -- but it's natural to assume that the company was sloppy with password security.

Victor told FoxNews.com that there was a major security breach at a PBS server earlier this year, where scores of PBS user names and passwords were exposed on the Internet. He believes the latest incident is connected to that earlier one.

"It could have been that the attacker was able to obtain the username and password for a producer at Sesame Street," Victor said.

Producers of "Sesame Street" and representatives from YouTube did not comment on the incident.

NewsCore contributed to this report.