Suspended senator Mike Duffy faces 31 charges in relation to alleged misspending on living and travel expenses, as well as allegedly fraudulent contracts.

In total, Mounties say the charges -- including seven counts of fraud under $5,000, seven counts of fraud over $5,000, 15 counts of breach of trust, one count of bribery of a judicial official, and one count of fraud of government -- cover expenses of more than $200,000.

"We have assisted the RCMP throughout their investigation and congratulate them on the progress they have made. Those who break the rules must suffer the consequences," the prime minister's director of communications Jason MacDonald said in a statement released after details of the charges were revealed.

The charges come after a year-long RCMP investigation, during which investigators examined four years' worth of expense claims, phone records, thousands of emails, and interviews with witnesses from four separate provinces.

The RCMP began by looking into housing claims in relation to Duffy's residences in Prince Edward Island and Ottawa. Investigators then followed leads that led them to probe three other areas: Duffy's travel and personal expenses, consulting contracts he awarded, and the request and acceptance of a $90,000 cheque from former PMO chief of staff Nigel Wright.

"These charges are the result of a careful examination of all the facts," RCMP Assistant Commissioner Gilles Michaud told reporters Thursday morning.

Duffy's lawyer, Donald Bayne, says his client is innocent.

"Senator Duffy is thankful that the awful 16 months of waiting through a protracted and highly public police investigation is finally over, and we can move on to an impartial forum and fair hearing," Bayne said in a statement released ahead of the charges being revealed.

Duffy and his wife are believed to be at their Prince Edward Island home, the address at the heart of the controversy that sparked the initial RCMP investigations.

The Conservative party has tried to distance itself from Duffy's scandals since allegations of misspending began in December 2012. The former Conservative senator was suspended without pay in November 2013, along with senators Patrick Brazeau and Pamela Wallin.

Judgment and consequences

In the PMO statement, MacDonald wrote that, "The conduct described in the numerous charges against Mr. Duffy is disgraceful."

Representatives from both the federal NDP and Liberal parties said the charges against the suspended Conservative senator reflect poorly on the judgment of the prime minister who appointed him.

Liberal MP Marc Garneau said the charge of bribery implies that the prime minister was aware of wrongdoing, an allegation Stephen Harper has denied.

"I believe that the prime minister has knowledge of what actually happened," Garneau said. "I think that the public expects an answer and I hope that the government will finally provide those answers."

In the past, Duffy has threatened that Harper would be called to the stand if he's brought to trial.

Duffy is due to appear in an Ottawa court on September 16, one day after MPs are scheduled to return to the House of Commons.

With files from CTV's Ottawa Bureau Chief Robert Fife and The Canadian Press