The claim fuels speculation that Holmes had been planning to leave her superstar husband for months.
A source told the Hollywood Reporter that Bella had been surprised to be fired, but now felt that, in the wake of the split, “it all made sense”.
Cruise adopted his 19-year-old daughter with ex-wife number two Nicole Kidman. It is understood that Bella worked for Holmes’ clothing line, Holmes and Yang.
The source told the tabloid: “There was never any trouble between them. Bella called Katie ‘Mom.’ She was fired out of the blue, and once Katie filed for divorce, it all made sense.
“This was a carefully planned ambush.”
The publication also interviewed Karen De La Carriere, a former Scientology executive, who said that in standing up to Cruise, Holmes is also taking on Scientology.
“This was a very bold move on Katie’s part,” she said. “Katie ambushed Tom Cruise and in so doing outwitted some of the most controlling people on Earth.”