The effectiveness of the iPhone X Face ID biometric security system is, once again, being called into question after a video emerged today showing a 10-year-old unlocking his mother's iPhone using the feature.

"I set up the Face ID using my face, but the annoying part is, my 10-year-old son can unlock my phone using his face," the iPhone X owner says in the video (below).

Apple claims that the probability of a random person being able to unlock your iPhone X using Face ID is approximately one in a million, versus 1 in 50,000 for Touch ID. The company has warned that the probability of a "false match" is higher for "twins and siblings that look like you as well as among children under the age of 13, because their distinct facial features may not have fully developed."

Apple did not immediately respond to PCMag's request for comment.

The latest Face ID controversy comes just days after researchers with Vietnamese security firm Bkav Corporation claimed to have discovered a way to beat the iPhone X's Face ID feature using a mask, something Apple specifically said would not be possible. Apple has said its facial-matching neural network is "trained to spot and resist spoofing" and "defends against attempts to unlock your phone with photos or masks."

Meanwhile, Bloomberg late last month reported that Apple lowered the accuracy specification for Face ID to speed up iPhone X production, a claim that Apple has denied.