The elections were originally scheduled for 2006 but were delayed
Angola's main opposition party, Unita, has accused a state bank of spending millions of dollars on the ruling party's election campaign.
Unita said it had sent the authorities a document showing that the state-owned Angolan Development Bank (ADB) had given $42m to the ruling MPLA.
But the bank said the document was forged and denied any such transfer.
Angolans are due to go to the polls on Friday to elect a new parliament - the country's first election in 16 years.
Test of popularity
The ADB has threatened to sue Unita over the allegations.
Unita secretary general Abilio Kamalata Numa however told the AFP news agency he was ready to go to court.
"This is a battle we are accepting. We have started it and we will take it calmly to unmask and dismantle the corruption that has been posed in Angola by a group of Angolans," he said.
There have been frequent allegations that the MPLA is using state money to fund their campaigning for Friday's vote.
The vote is being seen as a test of popularity for the ruling party's leader, Mr Jose Eduardo dos Santos, who has been president for the past 29 years.
Friday's elections were originally scheduled for 2006 but have been delayed on a number of occasions.
Angola was ravaged by civil war for 27 years until a peace deal was finally signed to end hostilities between the MPLA and Unita in 2002.
The peace accord followed the death of long-time Unita leader Jonas Savimbi.
Angola's only previous elections, in 1992, sparked renewed fighting, after Savimbi rejected the results.
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