Some of the findings by the independent auditing firm Deloitte about Senator Pamela Wallin's expense claims are eye-catching and difficult to explain. The 95-page Deloitte report released Tuesday suggests Wallin should repay approximately $120,000 in claims it judges were made for expenses not related to Senate business, an amount that includes the $38,000 she has already voluntarily repaid.

Here are some of Deloitte's surprising conclusions.

1. Documents were altered by Wallin's office

Deloitte lists entries on a copy of an online calendar Wallin provided for the audit and compared them to backup copies Deloitte obtained from the Senate. The auditors list almost 400 entries on the backups, mostly to do with Wallin's activities in her role as a board director in several firms and organizations, that do not appear on the copy she gave to Deloitte. Because the copy Wallin provided was "non-forensic," Deloitte couldn't determine when the changes were made or who made them.

On Monday, Wallin told reporters she did not intend to deceive Deloitte, but "I was advised, partway through the process, that I should only include information relevant to the actual expenses being claimed. So we formatted our calendar accordingly."

2. Deloitte provides examples of some of the most puzzling alterations

In June 9, 2009, Wallin claimed Senate expenses for an awards dinner she said she attended for the Institute of Corporate Directors in Toronto, though the airline ticket indicates she didn't leave Ottawa until 8 p.m. and didn't arrive in Toronto until after 9 p.m. Through interviews and internet research, Deloitte determined Wallin didn't speak at the dinner in 2009, but rather one year earlier, in 2008, before she was appointed to the Senate. The auditors found Wallin's electronic calendar had been changed to add the awards dinner event and delete the 8 p.m. flight. 

The discrepancy is explained as a mistake in a July letter written by Wallin's lawyer to the auditors.

In another example, Deloitte notes Wallin made a partial expense claim for speaking at a Saskatchewan $100-a-plate event for four riding associations. On the Senate backup copy of Wallin's calendar, there was an entry that read "4 riding fundraiser." That notation was removed from the copy Wallin gave Deloitte.

3. Deloitte says 2012 Senate expense rules not greatly changed

Wallin has said that the auditing process is flawed because new rules drawn up in 2012 are being retroactively applied to her expense claims filed three years before. "The result is that travel expenses, which were approved and paid by Senate finance in 2009 in 2010, in 2011, have, in a number of cases, now been disallowed," she told reporters in the Senate foyer yesterday. However, Deloitte writes, "the overall principles of the [travel] policy did not change, i.e., the travel costs would be reimbursed if the purpose of the travel was to carry out the senator's parliamentary functions."

4. Deloitte finds Wallin lives most of the time in Toronto

Deloitte found Wallin spent 35 per cent of the time during the audit period from January 2009 to September 2012 in Toronto where she owns a home, and 27 per cent in Saskatchewan. The question of where she lives is important, because Wallin was appointed as a Saskatchewan senator and, constitutionally, must be a resident of that province. However, Deloitte says Senate rules about residence are unclear.