According to BBC reporter Chris Fox, the face unlock mechanism works even when the device owner has his eyes shut. He tried this with different users and the same thing happened.
"The Pixel 4 facial recognition works even if you're asleep/dead. That seems problematic #madebygoogle #pixel4," Chris tweeted along with a video.
The US based search engine giant was so sure about its Face Unlock's security that the company had removed all the fingerprint sensors from the Pixel 4 handsets.
Google seems to be aware of the problem, stating on a Pixel 4 help page that: "Your phone can also be unlocked by someone else if it's held up to your face, even if your eyes are closed. Keep your phone in a safe place, like your front pocket or handbag."
Google claims that the Pixel 4 Face Unlock meets the security requirements as a strong biometric and it is one of the most secure face unlock solutions.
The Google Pixel 4 comes with a starting price tag of $799 and Pixel 4 XL for $899. The phones will ship globally from October 24.
In terms of specifications, Pixel 4 features a 5.7-inch Full HD+ Smooth 90Hz display. The Pixel 4 XL, on the other hand, comes with a 6.3-inch Quad HD+ Smooth 90Hz display.
Both the devices are powered by Qualcomm Snapdragon 855 chipset.