OTTAWA — A Canadian government inquiry found Monday that former Prime Minister Brian Mulroney had acted inappropriately when he accepted “cash-stuffed envelopes” during three meetings with a German arms and aviation lobbyist.

In a harshly worded four-volume report, Justice Jeffrey J. Oliphant, who led the inquiry, repeatedly questioned the credibility of Mr. Mulroney and of the lobbyist, Karlheinz Schreiber, a German-born businessman who handed the former prime minister $225,000 to $300,000 in thousand-dollar bills in three separate meetings. The meetings took place after Mr. Mulroney had stepped down as prime minister.

The meetings, Justice Oliphant said in a news conference, go “a long way, in my view, to supporting my position that the financial dealings between Mr. Schreiber and Mr. Mulroney were inappropriate.”

Mr. Mulroney, who was prime minister from September 1984 to June 1993, said in a statement that he was “grateful that this unfortunate chapter is over,” adding, “I will leave it to others to assess the full impact of these events.”

The report did not include any findings that might obviously harm the political fortunes of the current Conservative government led by Stephen Harper, which established the inquiry. It did, however, raise questions in the House of Commons about the $2.1 million the government paid Mr. Mulroney in 1997 to settle a defamation lawsuit.

Mr. Mulroney brought the action against the government after news reports that the Royal Canadian Mounted Police had written the government of Switzerland to ask for assistance in an investigation of Mr. Mulroney and Mr. Schreiber.

At the time, Mr. Mulroney played down suggestions that he had significant dealings with Mr. Schreiber. “We would have a cup of coffee, I think, once or twice,” Mr. Mulroney told a government lawyer under oath.

Mr. Mulroney said in the inquiry that he had not disclosed the extent of his relationship with Mr. Schreiber or revealed the payments because a government lawyer did not ask the “correct question,” a position Justice Oliphant called “patently absurd.”

Justice Oliphant noted that it was difficult to sort out the facts of the case because Mr. Mulroney preferred to deal in cash and did not keep records. Among the difficulties, he said, was determining the exact amount of the payments.

Several Canadian journalists have reported that Mr. Mulroney received kickbacks from Mr. Schreiber in exchange for Air Canada’s $1.8 billion deal with Airbus, a client of Mr. Schreiber’s, in 1988, when the carrier was owned by the government. A spokeswoman for Airbus would not comment.

The inquiry was prohibited from reviewing the Airbus purchase, but it concluded that the money that Mr. Schreiber gave Mr. Mulroney originated with a shell company set up by Airbus in Liechtenstein “in connection with sales of Airbus aircraft to Air Canada.” It found, however, that Mr. Mulroney was not aware of that link.

The inquiry also said that Mr. Mulroney had an unwritten agreement with Mr. Schreiber to promote military vehicles made by Thyssen Industrie, also a Schreiber client, to foreign governments.