A relative reported Katherine missing over the weekend, with granddaughter Paris Jackson tweeting that she had not spoken to her in over a week.
Jermaine later publicly clarified that his mother was simply staying with family members and Katherine herself apparently assured police she is fine.
On Sunday, Jermaine took to Twitter again to post an explanation as to why his mother Katherine needed to take some personal time.
"Let me put to bed today's nonsense: as I made clear some days ago, Mother is safe and well in Arizona with her daughter and our sister, Rebbie, resting up on doctor's advice, so it is beyond me how she can be reported 'missing'," Jermaine wrote.
He continued: "This incredulous claim was made for reasons best known to the adult/s who filed it but it seems no accident that it comes after we, the sons and daughters, put in place care-taking for our own mother, taking her to Arizona in line with doctor's advice following a check-up.
"Furthermore, it dismays me that such an alarmist 'missing person' report has caused unnecessary anxiety among Michael's children who will understandably react to what they misunderstand, hear or are told. No-one is being 'blocked' from speaking with Mother. She is merely an 82-year-old woman following doctor's orders to rest-up and de-stress, away from phones and computers."
Jermaine concluded: "Everyone has been well aware of this within the family, but I would like to reiterate my reassurance to the outside world that Mother is fine. In the meantime, thank you for all your thoughts and concerns."
The Jackson family controversy erupted after several members alleged that the late Michael Jackson's will is not authentic.