OTTAWA - Brian Mulroney's former chief of staff backed his old confidante's account of his business relationship with arms lobbyist Karlheinz Schreiber, but could provide no corroborating details for a Commons committee.

In an hour of testimony peppered with failed recollections, Fred Doucet told MPs he acted as an unpaid "link'' as Schreiber contracted Mulroney to serve as an international lobbyist after the former Conservative prime minister left office in 1993.

Doucet said he sat at Mulroney's side throughout a 1994 meeting in New York during which he said Mulroney explained his international efforts to Schreiber over the course of more than an hour.

But Doucet, whose relationship with Mulroney goes back to their student days at St. Francis Xavier University in Nova Scotia, could not recall a single detail of Mulroney's efforts that would allow MPs on the the ethics committee to independently corroborate the story.

"I have no recollection . . . I don't recall,'' Doucet told an increasingly agitated committee chairman Paul Szabo, who was seeking details of Mulroney's international travelling companions.

It was a refrain heard repeatedly by the committee members.

Doucet said he had no recollection of setting up a key meeting Schreiber held with Mulroney at Harrington Lake just two days before Mulroney left office.

He was adamant, however, that it was Schreiber -- not Mulroney -- who asked him to arrange subsequent meetings, during which large sums of cash were handed by the arms lobbyist to Mulroney.

Doucet, despite being present for those meetings, said he was unaware of the cash transactions.

And he was also adamant that he never asked Schreiber to funnel proceeds to Mulroney from the 1988 sale of Airbus jets to Air Canada -- as Schreiber has alleged.

The Airbus controversy, and the $2.1 million libel settlement that Mulroney won from the Canadian government in 1997, is at the heart of the committee investigation.

Doucet accused Schreiber of making "a number of false statements involving me.''

And he also provided an unsigned "mandate'' document -- annotated by two different hand-writings and a scribbled date of Feb. 4, 2000 -- that Doucet said he'd worked out with Schreiber to explain Mulroney's lobbying work. The proposed Bearhead light armoured vehicle plant does not appear anywhere on the document.

Conservative MP Russ Heibert emerged from the committee hearing to call Doucet "a very credible witness.''

It's time for the committee to wrap up its work, said Heibert, and allow a public inquiry to commence.

Given the dearth of new information provided Tuesday by three separate witnesses, even Liberals on the committee appeared ready to throw in the towel

Liberal MP Robert Thibault said the committee format is not providing the "full research and cross-examination'' required to properly probe witnesses.

For instance, Thibault wondered why Doucet, still a well-connected lobbyist active in Ottawa, spent up to seven years doing "pro bono'' work between Mulroney and Schreiber after his paid lobbying role on a light armoured vehicle project ended in 1992.

It was just one of many unresolved questions raised by Tuesday's testimony.

Two witnesses, former Liberal cabinet minister Marc Lalonde and former lobbyist Greg Alford, told the committee that unlike Mulroney, they were never paid cash for their work for Schreiber.

Alford also testified that even though he was in charge of the Canadian lobbying effort for light armoured vehicles built by Germany's Thyssen, he would "not necessarily be aware'' if Mulroney was lobbying on the same file internationally.

The question of international as opposed to domestic lobbying is important, because Mulroney would have breached ethical guidelines he himself brought in had he lobbied for Thyssen in Canada.