Athif Sarwar, 32, was jailed for three years after a jury found him guilty of using the family cash-and-carry business to conceal VAT frauds amounting to more than 845,000.
Since the verdict in May 2007, Sarwar, from Mearnskirk, Glasgow, has protested his innocence. He was freed in January 2008 pending appeal.
He claims a miscarriage of justice saying there was not enough evidence to link him to the alleged scam at the United Wholesale warehouse in Maxwell Road, Glasgow, between February and April 2003. He also claims judge Lord Carloway should not have allowed the charge under the Proceeds of Crime Act to go to a jury.
Defence QC Mike Jones told the Court of Criminal Appeal in Edinburgh yesterday that if Sarwar had been cleared on that charge it would have been very difficult for the jury to find him guilty of a second Proceeds of Crime Act charge.
Sarwar also claimed the jury verdicts were perverse because another man, Mansoor Khan, then 43, from Giffnock, Glasgow, who was assistant manager at the warehouse, was cleared.
The hearing is expected to last for two weeks before Lord Hamilton, sitting with lords Osborne and Eassie.
Back in 1999 Mr Jones successfully defended Labour MP Mohammad Sarwar who had been accused of trying to bribe an election opponent during the contest for the Glasgow Central seat two years earlier. Mohammad Sarwar, who stood down at the last election, was in court yesterday to support his son.
During a six-week trial, the Crown said Athif Sarwar, then managing director of the wholesale cash and carry firm, had used the business to launder the money in return for a 10 per cent cut.
His legal team are also working on further possible grounds of appeal.
During the trial the prosecution claimed a mystery man known as "Ahmed" - said by Sarwar to be the VAT fraudster - was a fiction.
They now claim they have unearthed a man of the same name who was the target of a major tax and customs investigation over an international mobile phone business.
The hearing continues.