Redknapp, tipped to become the next England manager, has denied charges relating to a total of $295,000 paid into a secret account in Monaco when he was in charge of Portsmouth.
Redknapp, Portsmouth manager in two spells from 2002-2004 and 2005 to 2008, was involved in angry exchanges with prosecution lawyer John Black when challenged about his evidence in London's Southwark Crown Court.
"You think I put my hand on the bible and told lies? That's an insult, Mr Black, that's an insult," Redknapp shouted, Britain's Press Association reported.
Redknapp shook his head as Black ended his cross-examination by saying: "I suggest you have been telling the court a pack of lies."
With a voice trembling with emotion, Redknapp replied: "Everything I have told you is the truth, the whole truth and nothing but the truth, so help me God."
Redknapp and former Portsmouth chairman Milan Mandaric, who made the payments, are standing trial for tax evasion, charges which both deny. Mandaric is now chairman of Sheffield Wednesday.
Redknapp earlier told the court he misled a tabloid newspaper reporter over the payments to stop him publishing an embarrassing story on the day of the 2009 League Cup final.
He told journalist Rob Beasley from the now defunct News of the World that one payment was a bonus relating to the sale of England striker Peter Crouch to Aston Villa in 2002.
Beasley had been asking Redknapp about claims from Mandaric that the money was for investments outside of football.
"I don't have to tell Mr Beasley the truth. I have to tell police the truth, not Mr Beasley, he's a News of the World reporter," Redknapp said.
"I referred to it to him many times as my Crouch bonus," as "Crouch is an easy answer."
Redknapp added: "I just want to get Mr Beasley out the way - I just didn't want a story in the paper... I was going to come down to breakfast and all my players were going to be looking at the back page of the News of the World. It was going to be embarrassing."
Manchester United beat Spurs on penalties in the 2009 League Cup final after a scoreless draw.
In a rare lighter moment, Redknapp explained why he named his Monaco bank account Rosie 47, combining his dog's name and his own year of birth.
Redknapp told the court he used the pet's name because "I loved her to bits."
