Chelsea scout Hillion insists Kakuta deal was above-board
FIFA have ruled against Chelsea and Kakuta after Lens reported them over the move, which took place in 2007.
As well as handing out big fines, FIFA banned Chelsea from signing a player until 2011 - though the London giants are appealing this decision.
"His mother is widowed and was responsible for five children and had big financial difficulties," Hillion told La Voix du Nord.
"When we started to talk about a possible move to Chelsea, we asked her if she ever signed anything with Lens.
"She promised she had signed nothing, nothing at all. Six months later, sorting out her papers, she found a pre-contract. She didn't even know what it was."
Hillion also hit back at French clubs, who he says are just trying to make money out of their youngster players.
"French clubs try to appear as the innocent victims," he continued. "But that is a caricature. It is just money matter."