Randy Jackson's mother is furious with him for challenging his late brother Michael's will.

Katherine arranged for his siblings to sign a letter demanding the resignation of the estate's executors while Katherine was away in Arizona but she has given her son a good talking to since her return.

A source told RadarOnline: "Katherine was completely unaware that Randy had orchestrated his siblings signing a letter sent to the executors of Michael Jackson's estate demanding their immediate resignation.

"Now that Katherine has been home for a few days, she knows that Randy was the one that planned this, and she is absolutely furious for him doing so. Katherine has never had a stroke or a mini-stroke as the ridiculous letter says."

The source added that Katherine is reluctant to speak out against her children but she has made her disappointment known behind the scenes after Randy claimed the will was invalid.

The insider added: "Katherine will never speak out publicly against her children, it's just not who she is. Behind the scenes, however, Katherine is extremely upset and disappointed in Randy's actions that have brought so much unwanted chaos into all of their lives," a source close to the situation tells us."

The King of Pop's three children - 14-year-old Paris, Prince Michael, 15, and 10-year-old Blanket - have lived with Katherine since his death in 2009, but were placed under their cousin Tito Joe 'TJ' Jackson's guardianship last week.

Katherine is now seeking to share custody with her grandson and the Jackson family are hoping all of the recent drama is behind them.