"I am happy within myself," he said in an interview with Brazil's Globo television.
"Before saying nonsense -- that we hid this, or hid that -- they should prove it," he said.
On Thursday Neymar lost his appeal against a fine imposed by tax authorities in 2012 for irregularities in his income tax declaration.
The case involved the player's father, whom Neymar also defended in the Globo interview.
"My father is doing everything to ensure that I can just focus on playing football. He handles the books. But in the moment when you see someone you love suffering, it starts to hurt," the star forward said.
The $112,000 fine is unlikely to perturb the Brazilian star too much as he reportedly earns around $215,000 a week at European champions Barcelona.