The R&B star has placed an offer on a property eight doors down from the 'Keeping Up with the Kardashians' star's new mansion in Hidden Hills, California, but her mother is determined to stop the sale.
A source said: ''Kim and Kris are furious.
''Kris is even considering putting an offer on the house herself just to outbid Ray J.''
The 59-year-old star doesn't want Kim's ex-boyfriend to upset her husband, Kanye West, and daughter North, 19-months, but will have to spend a lot of money to prevent him from securing the house.
The insider added to Life & Style magazine: ''Kim and Kanye just got settled into their new home, and now here comes Ray J.
''The owners listed the property at $2.9 million and Ray put in a $2.7 million offer, so there's a good chance the owners will go for it.
''Kris is mulling over the possibility of paying him off to live elsewhere.''
Kim, 34, only moved into her new house over the festive season and a source close to the brunette beauty previously admitted she couldn't wait to move out of Kris' house where she had been living since she was pregnant with North.
The insider said: ''Kim can't wait to get into their new home.
''Living with Kris, her baby and husband wasn't the most ideal, but this will be their forever home. They can't wait for friends to stay with them!''