OTTAWA, ONTARIO (NYTIMES) - Last Christmas, Prime Minister Justin Trudeau of Canada and his family were basking in the Caribbean sun on a private island owned by the Aga Khan, the billionaire philanthropist and spiritual leader of Ismaili Muslims.

But after an adverse ruling Wednesday (Dec 20) about the vacation from Canada's conflict-of-interest and ethics commissioner, Trudeau said he would spend this holiday season at an official residence a short drive from Ottawa and in the Canadian Rockies.

In a 66-page report, Mary Dawson, the commissioner, said that Trudeau's 2016 vacation - and two other trips made by him or members of his family - broke four sections of Canada's conflict-of-interest law for Cabinet ministers, their staff members, senior public servants and others.

While Dawson imposed no penalty on the Prime Minister, her finding takes the luster off Trudeau's long-standing promise to run a government beyond reproach.

Dawson found that Trudeau was not a personal friend of the Aga Khan, at least not in the legal sense, and should not have accepted the holiday.

"Mr Trudeau must ensure that he has arranged his private affairs so that they are not incompatible with his public duties," Dawson wrote.

Adding to Trudeau's woes, the finding comes amid a separate examination of a possible conflict of interest related to the financial holdings of Bill Morneau, the minister of finance and one of the government's most prominent Cabinet ministers.

Speaking with reporters, Trudeau said he accepted the report's findings and would clear future personal holidays through the ethics commissioners' office. He also apologised.

"It is important that as we move forward, we learn from this mistake," Trudeau said.

The apology did not satisfy opposition parties in Parliament, whose members have repeatedly used the daily question period to challenge the Prime Minister about the trip.

"I had a lot of hope in this government, I had a lot of hope in this Prime Minister," Jagmeet Singh, the leader of the New Democratic Party, told reporters.

"What we've learned today is Prime Minister Justin Trudeau has broken the law - there is no other way to put it but that he has broken the law with respect to ethics."

Of Trudeau and his Liberal Party colleagues, Singh added, "They exist in a world where they don't understand the realities of everyday Canadians."

Canada has been a particular focus of the Aga Khan's charitable efforts, in part because the country accepted about 7,000 Ismaili Muslims as refugees in 1971 after they had been expelled from Uganda by the dictator Idi Amin.

Last year, according to tax records, the government of Canada gave C$49 million to the Aga Khan Foundation Canada. The previous Conservative government matched a donation from the Aga Khan of C$30 million to open a Global Centre for Pluralism in Ottawa. The Aga Khan has also set up other institutions in Canada, without any government contribution, including a major museum of Muslim art in Toronto.

The ethics investigation hinged on two questions. The first was whether Trudeau broke Canadian law by accepting a ride on the Aga Khan's personal helicopter from Nassau to the compound at Bells Cay. The other issue was whether the Aga Khan was Trudeau's personal friend. Under Canadian law, the prime minister can accept gifts like holidays from friends and family members.

Pierre Trudeau, the former prime minister and Justin Trudeau's father, was close to the Aga Khan, whom he first met during the 1960s. The elder Trudeau welcomed the refugees from Uganda at the Aga Khan's request.

Repeatedly on Wednesday, Justin Trudeau described the Aga Khan as a "close family friend". But in her report, Dawson found that their only contact between 1983 and 2013 was at the funeral of Pierre Trudeau 17 years ago, when the Aga Khan served as a pallbearer.

"There were no private interactions between Mr Trudeau and the Aga Khan until Mr Trudeau became leader of the Liberal Party of Canada," Dawson wrote. "This led me to conclude that their relationship cannot be described as one of friends for the purposes of the Act."

And while the report supported Trudeau's earlier comments in which he said that the Royal Canadian Mounted Police recommended that for security reasons he use the Aga Khan's helicopter for the 65-mile trip to the island retreat, Dawson rejected his contention that there were no other viable travel options.

"The circumstances surrounding the acceptance of the private air travel were not exceptional," she wrote. Canadian Cabinet ministers and other public officials were barred from accepting flights on private aircraft several years ago after it emerged that some corporations were regularly providing them with air service.

While opposition politicians had focused on the trip last Christmas, the report found that Trudeau or his family members have been the guests of the Aga Khan on three occasions. Their first trip came in December 2014. And in March 2016, Trudeau's wife, Sophie Grégoire Trudeau, and a friend travelled with their children to the island.

Justin Trudeau said on Wednesday that his family had a "standing invitation from the Aga Khan".