Facebook has removed several videos showing teenagers being allegedly tortured, stripped naked and kept in solitary confinement at a juvenile detention center in Darwin, the capital city of Northern Territory, Australia. The footage, which aired on the Australian Broadcasting Corp.'s investigative program "Four Corners" Monday, was filmed between 2010 and 2015.

Four Corners Executive Producer Sally Neighbour said Tuesday that the videos were removed from Facebook. A representative for the social networking site told Mashable that two of the videos from the news story alleging torture of children at the detention center were reported and removed for containing child nudity. One of the videos contain footage of the tear-gassing of six boys at Darwin's Don Dale Youth Detention Centre in 2014 and has been restored upon further review, the representative said.

"The second video does contain child nudity and so we cannot restore it," the representative told Mashable. "Our Community Standards do not allow any nudity of minors to be shared on our services, even if they are shared with the purpose of condemning it.

"We review millions of reports each week and from time to time we make a mistake and work to rectify this where we become aware of this."

Australian Prime Minister Malcolm Turnbull ordered an investigation Tuesday into the incident.

"We are determined to get to the bottom of this, we're determined to examine the extent to which there has been a culture of abuse and, indeed, whether there has been a culture of a cover-up," Turnbull told reporters. "Why was this abuse, this mistreatment, unrevealed for so long?"

Human rights activists said that they had previously raised the issue of child abuse at the detention center, and accused the government of ignoring the issue.

"Amnesty International has repeatedly raised concerns of abuse of children being held in youth detention centers in the Northern Territory," Julian Cleary, indigenous rights campaigner at Amnesty International Australia, said in a statement. "As this program shows, these are not isolated incidents. The (Northern Territory) Government has failed to deal with systemic issues with the treatment of children in its youth detention system."

Northern Territory Chief Minister Adam Giles reportedly said he came to know about the footage only after it was aired Monday, and blamed a "culture of cover-up" within the corrections system. 

"I sat and watched the footage and recognized horror through my eyes," Giles told reporters in Darwin, adding that the Northern Territory Corrections Minister John Elferink has been removed from his position Tuesday.

He also said that the Royal Commission — Australia's highest form of inquiry — was expected to begin holding hearings as early as September, with a final report due to be released early next year.