Momager Kris Jenner (R) with her daughters Kim Kardashian (L), Kourtney( 2nd left) and Khloe (2nd right).

Los Angeles police subdued a man that broke into Kris Jenner's mansion and came face-to-face with Kim Kardashian.

According to TMZ, the unidentified intruder, who hails from Arizona, somehow got past security and started walking around the reality star's Calabasas property and peering through the windows.

Kardashian is said to have alerted police after she spotted the stalker in the gated multi-million dollar home.

Although he quickly fled the scene, he was found a few blocks away by officers from the L.A. County Sheriff, who claimed that he "reeked of body odour".

Following his arrest, he allegedly told officers that he was Kendall Jenner's boyfriend and Justin Bieber's stepbrother.

The man was placed on a 5150 psychiatric hold.

Earlier in March, it was reported that Jenner, the Kardashian matriarch and momager, was being blackmailed by a man who was threatening to leak a sex tape allegedly featuring her.

"The man has been demanding money from Kris. If he's not paid, he claims, he'll release the tape," a source told celebrity gossip site RadarOnline.

"He called Kris more than one hundred times in the last seven days, from more than 100 different phone numbers - he uses scrambled cell numbers. He called more than 25 times on Sunday alone."

It is not known whether both incidents are related.