From Memoirs of Sir Ewen Cameron.... by John Drummond:
The Camerons have a tradition, that they are originaly (sic) descended from a younger son of one of the Kings of Denmark, who assisted at the restoration of King Fergus the Second in the year 404, and that Prince was called Cameron from his crooked nose, as the word imports, which name he transmitted to his posterity. But it seems more probable that they are of the aborigines, the antient Scots or Caledonians, the first planted the country.
I've seen the above information repeated in other publications.
Added to the above characterization:
"With this last conclusion I am fully disposed to agree, but John Major has placed the matter beyond a doubt, for in mentioning on one occasion that clan Chattan and the clan Cameron, he says, “Hae tribus sunt consaguineae.” They therefore formed a part of the extensive tribe of Moray, and followed the chief of that race until the tribe became broken up, in consequence of the success of the Macintoshes in the conflict on the North Inch of Perth in 1396. Although the Macphersons for the time submitted to the Macintosh as captain of the clan, the Camerons seem to have separated themselves from the main stock, and to have assumed independence."
This site seems to refute the above information.
Let us trace the true origin of those Lochaber tribes formerly associated with Clan Chattan, particularly the MacMartins, the MacGillonies, and the MacSorlies, who were forced to change their name to Cameron and come under the banner of this Anglo-Norman family. Each of these tribes is given a page for that purpose.