The Prime Minister’s Office says the RCMP has not asked it for an email detailing a $90,000 payment to Sen. Mike Duffy from Stephen Harper’s former chief of staff.

CTV News reported Tuesday that the PMO has been withholding the email, but the office says that’s not true.

Spokesperson Julie Vaux said Wednesday “our office has not been asked for this email,” but also said the PMO is assisting the RCMP investigation into the $90,000 cheque Nigel Wright wrote to Duffy to cover the senator’s improperly claimed living expenses.

The Feb. 20 email describes the secret deal between Harper’s former right-hand man and Duffy, whose spending and residency claims were being audited.

CTV News first revealed the contents of the email two months ago. The prime minister’s communications director, Andrew MacDougall, recently confirmed to CTV’s Ottawa Bureau Chief Robert Fife that the email exists.

MacDougall said Wednesday that “we stand ready to provide any and all assistance or information requested.”

CTV News has confirmed that the RCMP interviewed Senators Marjory LeBreton and Carolyn Stewart-Olsen earlier this month as part of its ongoing investigation into the Senate expenses scandal.

Former RCMP Supt. Garry Clement said the Mounties could obtain a search warrant if the PMO does not hand over the email.

“The PMO is not sacrosanct, and therefore, a warrant issued properly by judicial authority, they have to co-operate,” he told CTV.

In the email, Duffy tells his lawyer that Wright worked out a “scenario” where all of the senator’s invalid expenses would be covered, including “cash for the repayment,” and the government would use its influence to blunt the outcome of the external audit.

A Conservative-dominated Senate committee subsequently edited the original audit of Duffy’s expenses to remove damning findings.

Amid the controversy, Wright resigned and Duffy left the Conservative caucus.

RCMP affidavits allege that three other senior PMO staffers knew about the Wright-Duffy deal.

Harper has maintained that Wright acted alone when he wrote a cheque to the embattled senator.

On Wednesday, the opposition criticized the PMO for its statements about the email.

“Instead of engaging in this proactive disclosure, they seem to be hiding behind weasel words like, ‘No one asked for this particular email,’” NDP MP Jack Harris told CTV. “There’s something wrong with that.”

Liberal Leader Justin Trudeau said he hoped an RCMP investigation would produce “some answers on this, but we see this government prefers to choose secrecy, cover up and spin.”

With a report from CTV’s Richard Madan and files from The Canadian Press