The RCMP has ended its probe into Nigel Wright, the former chief of staff to Prime Minister Stephen Harper, and his $90,000 payment to suspended Conservative Senator Mike Duffy.

The Mounties confirmed Tuesday that Wright won't face charges — a confirmation that likely brought sighs of relief from a number of people, but raises more questions with this phase of the investigation over.

Specifically:

What does the announcement mean for Wright?

What does it mean for Harper?

What does it mean for Duffy?

The RCMP said in a statement that its investigation into Wright is over.

"Upon completion of the investigation, we have concluded that the evidence gathered does not support criminal charges against Mr. Wright," Cpl. Lucy Shorey said in an email, noting the probe started last June.

Wright said in a statement to CBC News that he believed his actions were in the public interest and lawful.

"My intention was to secure the repayment of taxpayer funds," Wright said through his lawyer, Peter Mantas. He added that the RCMP's "detailed and thorough investigation has now upheld my position."

​Wright was being investigated for bribery, fraud and breach of trust over a payment to Duffy, who was suspended from the Senate without pay in November for filing ineligible expenses. He hasn't spoken publicly about the issue, but has issued a handful of statements through his lawyer.

In a short statement sent out after midnight, Duffy said, "After consulting my legal team, I have concluded it would be inappropriate for me to comment while these matters are under study by the RCMP."

Could be witness

The RCMP have confirmed Prime Minister Stephen Harper's former chief of staff, Nigel Wright, won't face criminal charges over a $90,000 payment to suspended Senator Mike Duffy. Harper, left, 'dismissed' Wright last May when word of the payment got out. (Prime Minister's Office) ​Wright resigned nearly a year ago after a media report revealed he had given Duffy a cheque for $90,172.24 to repay his Senate expenses debt. He remained in Ottawa, however, living just a few hundred metres from Parliament Hill, above a restaurant popular with staffers and journalists. Wright was frequently spotted around downtown Ottawa and continued his daily early-morning runs, at one point tracked down by a TV reporter and cameraman.

Wright, a longtime Harper supporter, was an executive at private equity firm Onex before he went to work in the Prime Minister's Office in January 2011. He told the RCMP that he is "financially comfortable" and didn't believe in submitting expense claims when he could afford to pay himself.

RCMP Const. Greg Horton said in an affidavit filed in court that Wright was incensed Duffy had run up such high expenses, including charging for meals that Duffy had eaten in his Kanata, Ont., home.

Wright took a leave of absence from Onex to be able to work for Harper. At the time he was named to the role, Wright told MPs on the House ethics committee that his leave of absence would become a voluntary resignation if he stayed with the government beyond January 2013. It's not clear whether that leave was extended. An Onex spokesperson told CBC News last year that the company looked forward to Wright's return once he was done as chief of staff to Harper.

Gerry Schwartz, president and CEO of Onex, on Tuesday praised Wright in a statement to CBC News.

"Nigel is a person of the utmost integrity. The RCMP decision is entirely appropriate and not unexpected," Schwartz said.

Wright has been told by the RCMP that he could be called as a witness in any court proceedings, sources told the CBC's Chris Hall.

Court documents also show the RCMP is investigating Duffy for fraud and breach of trust over his Senate expenses.

Harper 'pleased'

A spokesman for Harper issued a terse statement welcoming the news.

"We are pleased the RCMP has made progress in their work," Jason MacDonald said.

Nigel Wright is seen sitting next to International Trade Minister Ed Fast in 2012. (Adrian Wyld/Canadian Press) "The Prime Minister’s Office will continue offering every possible assistance to the RCMP's investigation."

Harper initially stood by Wright, with his last spokesman telling journalists that Wright enjoyed the full confidence of the prime minister. But that changed by the fall, after months of repeated questions over what Harper knew about Duffy's expenses and an agreement with Wright to soften a Senate report into Duffy's spending. Harper told an interviewer last October that Wright had been "dismissed."

After Harper lashed out in question period about Wright's "deception," senior Conservatives like Employment Minister Jason Kenney defended Wright.

NDP Leader Tom Mulcair said news that Wright won't be charged doesn't protect Harper, who Mulcair says has "refused to give clear answers to very simple, clear questions in the House."

"And the few times that he has given answers, he's contradicted himself from one day to the next," Mulcair said.

"I think Canadians still have a right to know exactly what went on, what the prime minister knew and when he knew it."

Duffy wouldn't repay

Duffy couldn't immediately be reached for comment.

News that Wright could be called on to testify may be uncomfortable for the senator named to represent Prince Edward Island. Wright gave the RCMP large amounts of information and spoke to investigators about the process of trying to convince Duffy to repay his Senate travel and living expenses.

The senator, who has since stepped down from the Conservative caucus, maintains he didn't do anything wrong. Two of his colleagues, Mac Harb and Patrick Brazeau, face charges of fraud and breach of trust over their Senate expense claims. All three are alleged to have claimed housing and living allowances to which they weren't entitled.

The RCMP also alleges Duffy paid a friend $65,000 for no apparent work.

The RCMP went through the stacks of emails provided by Wright as part of its investigation, some of which were released through court records made public last November.

The emails showed Wright didn't expect the RCMP to get involved in the furor over Duffy's expenses.

“I can’t figure out why the RCMP would have anything to do with this — unless there is clear fraud, which I have never heard,” Wright wrote in February 2013.

In May, Wright wrote, “I personally don’t think that Mike committed a crime at all — if I did, I would have pursued a different course."

'Self-serving politics'

Conflict of interest and ethics commissioner Mary Dawson is still reviewing Wright's payment to Duffy, a spokeswoman said.

"[She] has received confirmation from the Royal Canadian Mounted Police that the force is no longer investigating Mr. Nigel Wright and that criminal charges will not be laid against him. She is reviewing the matter and will not comment further at this time," Margot Booth said in an email to CBC News.

Last fall, a former law clerk from the House of Commons told the CBC's Leslie MacKinnon that it was hard to see what benefit the $90,000 gift conferred to Wright, the requirement for the criminal offence.

Rob Walsh suggested the demands Wright made of Duffy when he provided the money weren't a benefit to Wright.

"The funds were given to Duffy to bring the Duffy expenses controversy to an end, like settling a lawsuit. This is not fraud, nor is it breach of trust," Walsh said.

"I don't see any of this supporting criminal charges. It's just self-serving politics."