Facebook has come under fire for allegedly failing to remove sexualised pictures of children from its website.
Damian Collins, chairman of the Culture, Media and Sport Committee, expressed "grave doubts" at the social media giant's ability to moderate content.
The BBC said it used Facebook's "report button" to flag up 100 photos on the website but 82 were not removed, with an automated response saying they did not breach "community standards".
The images included under-16s in sexualised poses, pages aimed at paedophiles and an image appearing to be taken from a child abuse video.
Among the items not permitted under Facebook's community standards is "sexually suggestive content".
When examples of the images were sent to Facebook, the company instead reported the journalists to police for sharing the pictures, the broadcaster reported.
The BBC also said Facebook failed to remove the profiles of five convicted paedophiles.
Mr Collins said: "I find it very disturbing, I find that content unacceptable.
"I think it raises the question of how can users make effective complaints to Facebook about content that is disturbing, shouldn't be on the site, and have confidence that that will be acted upon."
Anne Longfield, the Children's Commissioner for England, said she was "very disappointed" by the revelations.