Court documents filed Tuesday by the RCMP indicate Senator Mike Duffy is being investigated for possibly committing breach of trust by using his Senate office budget to award consulting contracts of little or no value.

Here are some surprising things in the detailed 19-page document written by RCMP Cpl. Greg Horton about why he needs to see bank accounts belonging to a consultant hired by Duffy.

The documents include allegations that have not been proven in court. Contacted on Tuesday, Duffy told CBC News, "It would be inappropriate for me to comment while these matters are being examined by the RCMP."

1. The RCMP have enlisted forensic accounting help

The RCMP are able to dip into government departments for extra investigative help.

Mark Grenon, an employee with Public Works and Government Services Canada who is an accountant with a specialty in forensic accounting and a certified fraud investigator, has been seconded to the RCMP's sensitive investigations unit to examine Duffy's expense claims.

It was Grenon who spotted a lump sum in Duffy's expense accounts that appeared "disproportionately larger than other expenses."

2. Much of Duffy's office budget went to consultant friend

Duffy used a budget called "general expenses" to award consulting contracts to Gerald Donohue, a former TV technician who had an insulated concrete form business. The general expenses budget, says Horton, seems to be used to pay for the day to day operations of a Senate office and includes work senators commission to do with their Senate responsibilities.

Over half of Duffy's general expenses budget was spent on Donohue's contracts. That same budget was also used to purchase computers, printers, a coffee maker and a "music system."

3. Donohue billed for research for Duffy, but prepared no reports

Donohue issued invoices to Duffy for research on topics such as "the heritage project" or "aging in the Canadian population." But in an interview with the RCMP, Donohue said that Duffy asked him to prepare information on "obesity" or "being a Conservative." He also told the RCMP he never produced a document, report or product.

4. Other Duffy contractors didn't get paid as much as Donohue

The RCMP interviewed three other consultants who did work for Duffy. All three had other clients for whom they performed consulting work, and all had backgrounds in politics, government or business.

All three were able to describe in detail research they conducted for Duffy about topics such as industrial development proposals or the effect of the proposed Atlantic power accord on P.E.I. None of them were paid more than $3,000.

Yet Donohue was paid in sums of $10,000, $12,000, $13,000 and finally $24,000, sliced into payments of $2,000 over a period of a year. (Tax was added by Senate staff to Donohue's payments, bringing the total to $65,000).

5. Donohue was collecting disability insurance and not entitled to earn any income

Donohue told the RCMP he did not personally receive money from Duffy because he was collecting disability insurance and couldn't earn any income. The cheques from Duffy's office were paid to a media company Donohue set up, which did no media business and which later morphed into the concrete form company. The company, he said, consisted of his wife and son.

In March 2012, Donohue stopped accepting contracts from Duffy because, he said, he received a "personal statement" showing he was earning income, when in fact, he said, the income should have been in his company's name. He blamed the slip on Senate bureaucracy.