Sen. Mike Duffy had a high income but also substantial debt, a forensic accountant hired by the RCMP revealed in an Ottawa courtroom on Tuesday.

Forensic accountant Mark Grenon, who undertook a preliminary examination of the Senator’s expenses, accounts and tax returns, was giving testimony to a judge who is considering whether to accept the details into evidence.

Grenon noted that Duffy’s Royal Bank line of credit hit $100,000 in 2012 because of a “continued amount of overspending … that had to be funded with some sort of money.”

Grenon said the line of credit was paid off in four lump sums, including $80,000 deposited in March 2013, around the time Duffy received a $90,000 cheque to cover disallowed housing expenses from Nigel Wright, who was then chief of staff to the prime minister.

The judge also heard that Duffy’s net income ranged between from $118,422 to $134,668 between 2009 and 2012. That income was primarily from Duffy’s Senate salary and a CTV pension, though he also made thousands from speaking engagements.

Duffy trial

CTV News Legal Analyst Edward Prutschi said the Crown wants the details accepted as evidence to “show that Duffy was not sitting pretty financially, that he was having issues … where some months it was a little tough to meet the mortgage, other months it was a little tough to meet the line of credit.”

Such records could provide a motive, according to Prutschi, for a Senator to say to himself, “I need to take advantage of these expense reports a little bit, I need to find a way to get some of my expenses covered by the Senate that I know I’m not entitled to.”

Duffy has pleaded not guilty to 31 charges of fraud, breach of trust and bribery.

Defence lawyer Donald Bayne argued in front of Ontario Justice Charles Vaillancourt that the many financial records have little relevance to the trial and should not be allowed into evidence.

“You just let their dump truck back up to your courtroom and dump thousands and thousands of records ... and just leave it hanging there like a Sword of Damocles for the rest of the file," Bayne said.

"For what purpose?” he added. “Is Sen. Duffy in his defence then going to have to account for 5,500 transactions over his financial life? It will distort this trial and it’s misleading."

Duffy has previously commented on his line of credit. In October 2013, when he was about to be suspended from the Senate, he told the upper chamber that the Prime Minister's Office suggested using his debt as a cover for the $90,000 he received from Wright.

Duffy trial

"When they heard that I had been using a line of credit to renovate my home in Cavendish, they jumped right on it," Duffy said.

"It was suggested I go to the RBC, borrow the cash to pay off that line of credit, and then, when the media asked, 'Where did you get the money to pay the $90,000?' the PMO told me to say, 'My wife and I took out a loan at the Royal Bank."'

Duffy said at the time he did take out a loan, but it wasn't to repay the $90,000.

"That line was written by the PMO to deceive Canadians as to the real source of the $90,000,” he said at the time.

With files from CTV’s Katie Simpson, Philip Ling, and The Canadian Press and a report from CTV’s Katie Simpson