OTTAWA - A senior aide to Brian Mulroney obtained a special dispensation from federal conflict-of-interest rules and went to work lobbying for the Bear Head armoured vehicle project as soon as he left the Prime Minister's Office, a public inquiry heard Monday.

But Fred Doucet, the PMO staffer in question, testified that he couldn't remember any details about most of the phone calls and meetings he had on the project.

Nor could he recall writing a series of letters to German-Canadian businessman Karlheinz Schreiber about a separate controversy over the sale of European-built Airbus jets to Air Canada.

His memory was solid on only one point -- a 1994 meeting between Schreiber and Mulroney in which Doucet backed up the former prime minister's claims about his own contentious involvement in the Bear Head file.

The project, which would have seen the German firm Thyssen AG set up a plant in Nova Scotia to build and export light-armoured vehicles, is the main focus of the inquiry headed by Justice Jeffrey Oliphant.

Documents tabled Monday show that Doucet, who quit his post in Mulroney's office in August 1988, was holding discussions within three days with Frank Moores, the former Newfoundland premier who had become the chief Canadian lobbyist for Bear Head.

Doucet readily acknowledged he went on to lobby on behalf of Schreiber, who served as chairman of a Thyssen subsidiary established to handle the project.

But Doucet adamantly denied that a $90,000 cheque he collected from Schreiber in November 1988 was a "success fee" for talking a reluctant cabinet minister into backing the deal.

Previous evidence has shown then-defence minister Perrin Beatty was skeptical about the Bear Head proposal, and Schreiber has testified that he hired Doucet to get Beatty's signature on an understanding in principle about the deal.

Doucet told a drastically different story.

"I categorically deny ever asking Perrin Beatty to sign," he said. "That would have been a remarkable request on my part, which I would never have done."

The $90,000 he received from Schreiber, he insisted, was a retainer meant to cover future services, not a reward for work already done.

Doucet also testified that his primary duties for the two years prior to his departure from the PMO had been to organize Canadian participation in a series of international summits.

But inquiry counsel Richard Wolson noted that evidence gathered from Senator Lowell Murray, then the minister for Atlantic economic development, indicates Doucet also had a hand in other matters.

Wolson said he expects Murray to testify later this week that Doucet contacted him several times to discuss Bear Head while he still worked for Mulroney.

Under the federal ethics code in force at the time, Doucet would normally have been subject to a one-year cooling off period before being allowed to lobby any departments he had dealings with while in government.

But before leaving the PMO he had obtained a waiver of the cooling-off period in negotiations with Jean-Pierre Kingsley, then a senior official at Treasury Board.

When Wolson suggested that Kingsley would never have approved the arrangement if he'd been aware of prior involvement in Bear Head at the PMO, Doucet replied:

"I don't know that."

Diary entries and other documents show Doucet continued to lobby for Bear Head -- and to arrange meetings between Schreiber and Mulroney to discuss the project -- through 1992.

By that time the prospects for building a vehicle plant in Nova Scotia had dwindled, but Thyssen had floated a new proposal to locate a plant in Quebec.

Schreiber has said he eventually paid Mulroney $300,000 to lobby for the Quebec-based proposal. He claims the deal was struck just before Mulroney stepped down as prime minister in 1993, although the money didn't change hands until later.

Mulroney has admitted taking money from Schreiber but puts the total at $225,000 and says he broke no laws or ethics rules. He says his lobbying was directed not at Canadian officials but at foreign political leaders whose countries might have bought the Thyssen vehicles.

Doucet offered support for Mulroney's version of events Monday as he described a meeting he attended between Mulroney and Schreiber at a New York City hotel in 1994.

Doucet, largely reiterating testimony given previously to a parliamentary committee, said he remembers Mulroney outlining for Schreiber his lobbying efforts with former French president Francois Mitterrand and former Russian president Boris Yeltsin, as well as with unidentified Chinese leaders.

That flatly contradicts a long-standing claim by Schreiber that Mulroney was hired to lobby domestically -- something that could have put him in breach of the federal ethics code.

Doucet's memory grew cloudy, however, when he was asked bout three letters written to Schreiber in 1993-94 about the Airbus affair.

In the letters, which became public last year, Doucet referred to his efforts to clarify "confusion" over whether Air Canada had taken delivery of 32 or 34 Airbus jets.

He concluded the total was 34 and, in the last of the three letters, told Schreiber the matter was "very important" and he would discuss it further when they met in person.

Doucet testified Monday he had "absolutely no" recollection of writing any of the letters and couldn't explain what they were about.

Oliphant, whose mandate is confined primarily to issues arising from the Bear Head deal, appeared to have little appetite for pursuing the Schreiber-Doucet correspondence any further.

"I want to make it clear that it is not my intention -- because I have no authority to do so -- to turn this inquiry into an investigation of Airbus," said the judge.

Mulroney sued for libel, and won a $2.1-million settlement from the Liberal government of Jean Chretien, after the RCMP sent a letter to Swiss authorities in 1995 accusing him of conspiring with Schreiber and Frank Moores in an alleged kickback scheme arising from the Airbus deal.

No charges were ever laid against any of the men named by the Mounties.