NDP ethics critic Charlie Angus has written to the auditor general asking him to investigate "concerns around the Liberal Party of Canada using resources from the Senate of Canada to run their operations."

The only evidence Angus provides in the letter is a Thursday article in the Ottawa-based Hill Times, which suggests, "There has been an ongoing sharing of resources for partisan activity between Liberal members in the House of Commons and Liberal senators."

The Hill Times says its information comes from a "Liberal source" who did not want to be identified.

Angus also asked Auditor General Michael Ferguson to look at "possible money transfers between offices of members of the Senate and House of Commons," again offering the Hill Times article as the only evidence.

Ferguson is already investigating the expenses claimed by all senators, going back two years.

Senator James Cowan, the former Liberal Senate leader, told reporters Thursday that sometimes the results of research funded by Liberal Senate resources is shared with the Liberal caucus in the House of Commons.

Cowan is now the leader of the former Liberal senators' new caucus, which has been recognized by the Senate as an official party. The new caucus was formed Wednesday after Liberal Leader Justin Trudeau told Liberal senators they are expelled from his caucus and must sit in the Senate as independent senators.

Senators say they only share research results

Senator Grant Mitchell, the former Liberal Senate caucus chair, and now chair of the new caucus the ex-Liberal senators have formed, told CBC News only research documents are shared. "There's no way we can transfer money to the House of Commons." Asked if Senate money could be transferred to the Liberal research bureau, he replied, "We couldn't transfer money to them.… We couldn't even if we wanted to. It's not possible under the rules."

Former Progressive Conservative senator Lowell Murray, now retired, said in a phone interview from Margaree Forks, Cape Breton, that the Progressive Conservative side in the Senate used to share research with MPs, especially when his party was reduced to only two members in the House of Commons after the 1993 election.

Liberal ranks in the Commons were slashed after the 2011 election, although not as much. The party ceased being the Official Opposition and was cut down to fewer than 40 MPs. The loss of seats meant the party's research budget was curtailed.

Speaking to reporters in the foyer of the House of Commons Thursday, Liberal MP Dominic LeBlanc said, "I know that when we had a previous interim leader, there may have been more sharing of resources [between Liberals in the House of Commons and the Senate] but Mr. Trudeau reorganized his office in a way that taxed, almost exclusively, if not exclusively, House of Commons resources."

The previous interim leader is Bob Rae who resigned as an MP in June. In an email to CBC News Rae wrote he has no comment to make about LeBlanc's remarks.

Mobile users, read the pdf of the NDP letter here.