The 21-year-old, who starred in Brazil's successful Confederations Cup campaign in June, joined the Catalans for €57m in one of the most high-profile transfers of 2013. The total outlay has been confirmed by Barcelona.
However, Radio Globo reporters were leaked minutes from a Santos board meeting which shed new light on the detail of the agreement.
According to the documents, Barca paid €17.1m for the full ownership of Neymar, though just €9.35m went to the Brasileirao club with two companies that owned part of his registration - Teisa Group and DIS - splitting the other 45 per cent.
The report also claims the remaining €40m was paid in commission to other parties, including Neymar's father, as the Camp Nou club fought off competition from rivals such as Real Madrid, Chelsea and Manchester City.
Santos may receive more financial profit from the move eventually through arranged friendlies that the two sides agreed to, with the first on August 2 in Spain, and potential objectives for the forward to achieve which were included in the contract.
The documents also show that Neymar’s father wanted his son to depart Brazil ahead of the World Cup because he did not want him to become a "hero or villain" at next summer's tournament in the South American country.
The attacker, who has scored an impressive 24 goals in 39 Selecao appearances, will meet up with his new Barca team mates next week.