A leaked invoice suggests PDVSA, the state owned Venezuelan oil company, is paying a staggering US$46 million for its sponsorship of the Williams team in 2012.
Despite its authenticity having not been confirmed, the invoice from Williams - includes the Oxfordshire based team's correct Barclays bank account - requests the full amount in pounds sterling.
Also appearing on the internet in recent months were the full contract between team driver Pastor Maldonado and Williams, and a stamped letter from Venezuelan congressman Carlos Ramos.
The leaking of the documents, with the invoice now published on the website of the Spanish sports daily Marca, surrounds Venezuelan officials' doubts about the legality of Williams' lucrative PDVSA deal.
Ramos' letter to Williams' communications boss Claire Williams last November referred to an "ongoing investigation" by the Venezuelan parliament.
"You may ... be aware that our congress granted no approval to the sponsorship contract between Williams F1 and PDVSA," he wrote, demanding Williams divulge the "amount disbursed to date to Williams F1 by PDVSA".
Maldonado is backed directly by PDVSA, and is famously close to Venezuela's controversial president Hugo Chavez.