William O'Neil, 47, secured a mortgage for £78,500 for a property in Ruchill, Glasgow, in 2002. He was in prison at the time after being convicted the previous year of dealing heroin.
Claiming to be a company manager who earned £32,000, he was granted a loan from the Bank Of Scotland.
But in 2007, after being released, O'Neil sold the house and transferred cash from the proceeds of the sale to his partner Denise McNeil for her to apply for another mortgage on a £1.5million house.
The court was told the couple were "enchanted" with the house she bought, which was known as Hayhill.
After a 12-day trial at Glasgow Sheriff Court O'Neil, of Bardowie Road, Milngavie, was convicted by jury of a mortgage fraud and a money laundering charge.
His sister Deborah Hayburn, 49, from Drumfearn Road, Possilpark, Glasgow, was found guilty of the same charges by re-mortgaging her property for £127,890 by giving the bank false income information, before selling up and transferring £124,755 to McNeil.
Ex-model McNeil was also found guilty of mortgage fraud by falsely claiming to the bank she earned £300,000 from being the owner of a cafe, Bank Roll, which secured her a £975,000 mortgage.
Hayburn was jailed for two years and McNeil for three years for their crimes.
Passing sentence, Sheriff Sam Cathcart said he was imposing custodial sentences due to the "gravity of the offences".
O'Neil had been jailed for seven years in 2001 at the High Court in Glasgow after being caught with £250,000 of heroin.
His fraud trial heard that between January and September 2002, a mortgage application for what was plot 153 Hillgrove Gardens and is now 1 Colgrain Terrace, was submitted on his behalf - and signed.
It claimed he was a manager at Indowood Limited, a furniture retail firm, and that he earned £32,000 and lived at 2 Parkside Gardens, Glasgow. What the bank was not told was that he was in Glenochil Prison at the time.
The court heard that despite a process being followed to give O'Neil a mortgage, nobody dealt with him face to face.
O'Neil told the jury that after paying a deposit for a plot of land he was due to buy a house on, he found himself in prison and that he asked his dad, William, to sort a mortgage for him.
In his speech to the jury, O'Neil's defence counsel Mark Moir said: "I would suggest to you that is exactly what happened.
"It happened here because we had greedy brokers, greedy lawyers and greedy bankers. All were interested in getting the commission."
He said there was "a culture of just pushing mortgages through".
But procurator fiscal depute Blair Speed showed a mortgage application with a signature and O'Neil's details on it, including that he was a warehouse manager and earned £32,000, and asked the jury to infer that he was involved in the process.
O'Neil claimed that although in prison he was the director of a company named Indowood, and had the funds to pay his mortgage.
The court heard from Bank Of Scotland worker Stuart Blackburn. He gave evidence at the trial on behalf of the bank but had no involvement in O'Neil's mortgage.
When addressing the court Mr Moir said his client did not accept he was guilty.
O'Neil founded Art & Soul Glasgow in 2007, which sold Howson's work. But O'Neil was accused of ripping off the artist, an Asperger's sufferer.