The influence peddling allegations against a former senior staffer in the Prime Minister's Office raises serious questions about whether Prime Minister Stephen Harper can be trusted, Liberal Leader Michael Ignatieff said Thursday.

Harper's office called the RCMP Wednesday after hearing aide Bruce Carson allegedly promised First Nations bands and companies access to the prime minister in exchange for money.

The allegations sprung from a news investigation by Aboriginal Peoples Television Network, which said Carson was lobbying the Indian and Northern Affairs Canada and the minister's office for an Ottawa-based water company.

A spokesperson for Indian Affairs Minister John Duncan said the minister had not met with Duncan, but a staff member had once.

"Mr. Carson briefed the staff on the proposed water project," Michelle Yao said in an email to The Canadian Press. "Staff provided publicly available information to Bruce Carson and recommended he work directly with First Nations."

On Wednesday, the PMO also denied the allegations.

Harper "has never met with, been spoken to or been lobbied by Bruce Carson on any of these matters," the PMO said in a statement to CTV News.

Ignatieff said the allegations relay the "serious ethical lapses" of the Harper government.

"This is raising fundamental questions about whether Stephen Harper can be trusted with power," Ignatieff said, also speaking of two possible cases of contempt of Parliament.

It is also the second time in a week the Conservative government has asked the RCMP to investigate a former staffer. The first was a former aide whom the Information Commissioner said interfered in Access to Information requests.