Reviled vlogger Mike Martin, better known as "Daddyofive", has tried to claim that his cruel YouTube "pranks" are all fake amid a storm of accusations that he and his wife Heather are child abusers.

Unfortunately for Martin, another vlogger unearthed clips deleted from the Daddyofive YouTube page that show the Maryland father encouraging one of his sons to slap his daughter in the face.

"You know you don't hit girls," Martin tells Alex.

"But she's your sister so she don't count."

Alex is clearly reluctant to hit his sister but eventually belts her in the face after his father continues to badger him to do so.

Emma instantly dissolves into tears, but Martin, apparently amused by his son's action, does nothing to comfort her.

A bottle is then thrown against Alex's head, though it is not clear whether it was thrown by Martin or his nine-year-old son Cody, who is a constant target of the family's "practical jokes".

The slap video surfaced on the same day that Martin and his wife claimed yet again that the cotroversy their channel has attracted is "tearing their family apart".

"The videos are fake. They're fake," Martin says in the latest post, which is entitled "Family Destroyed Over False Aquisations" (sic).

"They're over-exaggerated, some videos are scripted, I mean they're just played out, they're the kids ideas we just act them out."

But this defence is unlikely to do anything to stop the fearsome backlash against Martin and his wife, who have been heavily criticised this week for the way they treat their children.

The hammer started to come down hard after a Philly Voice columnist accused the pair of using their children as "shields", following an outcry over a video in which the parents falsely accused young Cody of splashing ink on a carpet.

Even those with a more mild reaction to Daddyofive's asinine schtick have voiced their disgust over the slapping video, among them "KEEMSTAR", another YouTuber who recently interviewed Martin for his show "Drama Alert".

"The other stuff I could write off, you know," "Keem" said in a Twitter video earlier today.

"The boys beating each other up, I mean that just seems like typical growing up with brothers type stuff…but when I saw the clip today where…the brother slapped the girl?