As legislators resume their probe Monday into irregularities in the management of the RCMP's pension fund, they'll hear more from a former sergeant who — according to memos obtained by the CBC — questioned whether his office was involved in a "coverup."

Among those expected to sit before the committee when it resumes mid-afternoon is retired RCMP Sgt. Keith Estabrooks, who testified two weeks earlier. Memos he had written in 2006 detail his concerns about possible corruption within the force.

The CBC has obtained copies of those internal memos, which accuse RCMP Deputy Commissioner Paul Gauvin of interfering with an investigation into irregularities in the management of the pension and insurance fund.

In one memo to his boss in the force's access to information section, dated April 13, 2006, Estabrooks questions whether his office is "assisting in some sort of coverup."

Estabrooks — who has retired as a sergeant but still works at the access to information section — wrote an earlier memo (dated March 23, 2006) that specifically accused Gauvin of unethical conduct.

Estabrooks told the parliamentary committee the April memo that speculated about a "coverup" had disappeared from the official file.

However, Estabrooks said he had kept a copy of the missing note and handed it over to the committee.

The March 2006 memo discusses the treatment of a report by the Ottawa police force, which alleged fraud involving the Mounties' pension and insurance funds. Estabrooks handled the report in 2006.

In the memo, Estabrooks questions an order to allow Gauvin to see the final edited police report before it could be made available to the public through Access to Information laws.

Estabrooks wrote in the memo that since Gauvin was a key player in the pension matter, "just the fact that he has access to the documents is a conflict and unethical."

"It is my opinion that Mr. Gauvin is in a direct conflict of interest by having anything to do with the release of our proposed package as he is a key player in the pension matter," the March 2006 memo reads.

Estabrooks also suggested reporting the matter to the ethics commissioner as soon as possible.

Liberal MP Borys Wrzesnewskyj, who sits on the parliamentary committee, warned of "very serious consequences" if the memo trail "clearly spells it out that there was obstruction" and it proves to be true.

Gauvin is also expected to testify later Monday.