Gilbert Myles, a former Member of Parliament, has had an appeal against a conviction of perverting the course of justice, denied by the Court of Appeal.
Myles was found guilty last year of faking a receipt book while being investigated for fraud and was sentenced to community detention and community work.
He was found not guilty on the fraud charges.
The Court of Appeal ruling says Myles' actions were intended to persuade the Serious Fraud Office not to lay fraud charges, or if charges were laid, he created evidence to defend them.
Myles was an MP for the National Party, the Alliance Party and New Zealand First between 1990 - 2000.