The actor generously donated a sizeable sum to help the cause, and then challenged the PM to follow in his footsteps.
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In a video posted on his Facebook page on Monday, Leo, 39, happily accepts David Beckham’s nomination to be soaked with icy water.
Explaining that he is currently at Lake Athabasca in Canada learning about the effect of Canadian tar sands on our climate, the star calls out Canadian Prime Minister Stephen Harper to take part in the challenge, moments before a bucket of freezing water is poured over his head.
According to numerous reports, he also donated a huge $100,000 to the ALS Association on behalf of the Leonardo DiCaprio Foundation.
The viral Ice Bucket Challenge has so far raised almost $80million for ALS research. At the weekend, a number of other stars added their names to the list of celebrities taking part in the campaign, including Jennifer Aniston, who can be seen getting a kiss from fiancée Justin Theroux after completing the challenge, in a sweet video posted online.