In a statement posted on her website, Jenna Miscavige Hill, niece of church leader David Miscavige, said: “My experience in growing up in Scientology is that it is both mentally and at times physically abusive.”
“As a mother myself, I offer my support to Katie and wish for her all of the strength she will need to do what is best for her and her daughter,” wrote the 28-year-old, who left the controversial church in 2005, according to the New York Daily News.
Holmes, an actor, has filed for divorce and taken up residence in New York. Websites in the US said she and Cruise and have cut off all contact with each other, and have both hired heavyweight lawyers to represent them. Cruise reportedly calls his daughter once a day.
There were meanwhile further accounts of turmoil in the family of Mr Miscavige, a close friend of the superstar actor.
Ron Miscavige has reportedly fled the church’s heavily guarded International Base in rural California. He and his wife were allegedly followed by Scientology security teams who tried and failed to get them to return.
Renewed attention has meanwhile been paid to the fate of Mr Miscavige’s wife Shelly, who went missing in 2007.
Her disappearance has prompted various theories. One is that Mrs Miscavige, who would now be in her 50s, is in hiding after fleeing the religion.
Some believe she died after a battle with cancer, while some former Scientology members assume she was sent for a retraining programme at a secret location known within the church as “the Hole”.
The anti-Scientology group Why We Protest has launched a campaign to find her, but has received few leads.