Vancouver writer and former prosecutor Sandy Garossino has presented a compelling argument that the RCMP should reopen its investigation into Mike Duffy case. 

She based this, in part, on UBC law professor Benjamin Perrin's testimony at the senator's trial.

Perrin was legal counsel to the prime minister when former chief of staff Nigel Wright wrote a $90,000 cheque to Duffy to cover his expenses.

Last week, Perrin stated under oath that he believed that Harper knew of the $90,000 payment to Duffy. It's something Harper has repeatedly denied.

Garossino has even quoted a former Vancouver police investigator who said that in light of Perrin's testimony, the RCMP should interview Conservative Leader Stephen Harper.

The stakes are high for the Mounties should they choose to reopen the Duffy case.

That's because the prime minister can have a profound impact on the national police force's funding.

It's an issue that author Paul Palango has raised in three books about the Mounties.

"They know that, to be effective law enforcement officers, they must be independent of government, but almost to a man or woman these days, Mounties feel they have become subject to political control," Palango wrote in The Last Guardians: The Crisis in the RCMP...and in Canada. "The rule of law has been subverted by the rule of politics."

In late 2005, the RCMP revealed the existence of a politically charged criminal investigation during a federal-election campaign.

It involved then Liberal finance minister Ralph Goodale's office in connection with its handling of rules around income trusts.

The RCMP commissioner at the time, Giuliano Zaccardelli, reportedly instructed staff to put Goodale's name in the Mounties' news release.

Goodale and his staff were cleared, but the revelation contributed to the Conservatives winning the election.

After Harper became prime minister, he introduced tough-on-crime laws that were welcomed by organizations representing Canadian police officers.

More recently, an RCMP investigation led to 31 criminal charges, including bribery, against Duffy. 

But the person who gave Duffy the money—Harper's former chief of staff—wasn't charged. Nor was Harper's current chief of staff who, according to Perrin, was in the room when this payment was being discussed.

It's clear that RCMP commissioner Bob Paulson has the authority to operate independently of political interference and there's no evidence that this didn't occur in the Duffy investigation.

Meanwhile, Paulson has in the past appeared before a parliamentary committee to make the case for more financial resources.

It's not an ideal situation for Canadians who rely on the Mounties to serve as unbiased players in the political process.