Canadian Prime Minister Justin Trudeau is under investigation for a holiday he took on a private island belonging to a billionaire spiritual leader.

Canada’s federal conflict-of-interest and ethics office said it was probing whether the visit to the island, which took place over the new year, broke rules preventing ministers from accepting bribes.

Mr Trudeau said he was “more than happy” to answer the commissioner’s questions.

The island is owned by Prince Shah Karim Al Hussaini Aga Khan - leader to the world’s 15 million Ismaili Muslims, a denomination of Shia Islam.

He also heads a foundation that is a registered lobbyist that has received hundred of millions in grants from the federal government in recent decades

The 71-year-old is a close family friend of the Canadian Prime Minister and was an honorary pallbearer at the funeral of Mr Trudeau's father, Pierre.

Justin Trudeau vows to defend women and stick up to Trump

He chairs a development network, which promotes investment in Asia and Africa, and is considered the world’s 11th richest royals – just ahead of the Queen – according to Forbes.

Mr Trudeau was accompanied on the trip to the billionaire's island by his family and two fellow Liberal politicians: MP Seamus O'Reagan and Party President Anna Gainey.

The destination of the visit was initially kept secret, with the Prime Minister's office claiming it was necessary to protect the Trudeau family's privacy.

But after news of the location leaked, Mr Trudeau went on the record about the vacation, admitting using the Aga Khan's private helicopter.

Mr Trudeau defended the secrecy shrouding the visit at a press conference: "This was our personal family vacation and the questions you're asking, I allow you to reflect on them."

Yet the helicopter ride the prime minister admitted to taking may violate rules introduced underhis own leadership, which bans government ministers from accepting sponsored travel on private aircraft without permission from the ethics commissioner.

The Canadian leader is also under investigation for separate allegations that he broke conflict-of-interest laws by attending Liberal Party fundraisers where small groups met with him after making 1,500 Canadian dollar (£946) donations.

Justin Trudeau Show all 8 1 /8 Justin Trudeau Justin Trudeau Day out The family get in the boat with climate change AP Justin Trudeau Keeping fit Jogging over the Alexandria bridge with the Mexican president AP Justin Trudeau Family comes first “Sophie inspires me every day to be better. I wouldn’t be here tonight if it weren’t for her leadership and her example." AP Justin Trudeau Three-way handshake Trudeau has vowed to strengthen international relations. Twitter Justin Trudeau Bromance Friendship with the White House The White House Justin Trudeau Pandas Just because. Twitter Justin Trudeau Yoga The plank became an internet sensation Twitter Justin Trudeau Making history Trudeau's gender-balanced cabinet was the first of its kind AP

The two inquiries, which are the first time Mr Trudeau has been investigated for breaching such ethics rules, threaten to undermine Mr Trudeau's claims of leading an "open and transparent" government.

Yet fall-out from the probes will only be political, since the ethics office can only hand out small fines.