Former party treasurer John Brayshaw refused to sign off the party's accounts because he claims he was not given the access to all the records he needed to see.
In 2005 he wrote to the Electoral Commission, the body which oversees political party finances, saying that he resigned as BNP treasurer. He alleged a number of irregularities had come to light including missing invoices and receipts from the Trafalgar Club.
In his letter, Mr Brayshaw said current party treasurer John Walker and his deputy David Hannam visited his home for a week to complete the accounts.
He said he did not help them but claimed he witnessed some unusual activities, namely the shredding of a large number of documents and invoices.
Mr Brayshaw said he was told to burn the shredded documents, but kept them because he felt something improper had taken place.
A black bin bag containing the documents has been handed to File On 4.
It contains fragments of cheques, train tickets, receipts and invoices.
Some of the fragments carry the names of Nick Griffin, his parents and even the Trafalgar Club.
One unshredded item is a petrol receipt with the name Excalibur - the title of the party's merchandising arm.
Under tax regulations all financial records should be kept for six years.
The Electoral Commission said it had no reason to believe a breach of the party funding law had taken place.
Current BNP treasurer John Walker dismissed Mr Brayshaw's allegations as pure fantasy.
He said Mr Brayshaw had failed to make the books balance and had left the party's accounts in a mess.