The estate filed documents recently asking for the executors to ''expenses relating to a residence in Las Vegas,'' which is a house belonging to the showbiz matriarch's daughter Janet Jackson.
It was previously believed the claim related to partial mortgage payments on the property, but sources tell gossip website TMZ that Janet owns the house outright, and the expenses are actually for ''food, cable, utilities, Internet, travel and even toilet paper.''
The insiders stated that Janet never spends time at the Las Vegas house and bought it specifically for the use of her mother, who is the legal co-guardian of the late King of Pop's three children, Prince, 15, Paris, 14, and 10-year-old Blanket.
A hearing is pending on the request, which was submitted before the 'Together Again' singer and some of her siblings called for the executors of Michael's estate to resign, claiming his will was a fake.
It was recently reported that Katherine is refusing to speak to Janet or her other children Randy and Rebbie Jackson because she feels they deliberately prevented her grandchildren from contacting her when she made an unplanned trip to a spa in Arizona.
The siblings are reportedly banned from entering the home in Calabasas where Katherine lives with her grandchildren because they are at war with the executors of Michael's estate - which pays for the property - but their mother is said to be ''heartbroken'' over their recent behaviour and doesn't want to see them.
The problems began when Janet, Rebbie, Randy and their brothers Jermaine and Tito sent a letter to Michael's estate executors John Branca and John McClain demanding their resignation. However, Jermaine and Tito later released statements in which they said they regretted signing the document.