I see that Fred255 commented by saying,

it does not sound right to me.

Agreed. 

He also said,

Just because you enter a competition does not mean you hand them
the copyright

Ummmmm ... careful.  If the contest rules state that they can reuse any/all
photos that were submitted ... and you submit a photo ... that means that
by submitting a photo, you entered the contest, and you agreed to their
rules ... and that could include permitting their reuse of the photo. 

I am not trying to suggest that all contests have that rule or that contest
(or any other contest) should have that rule -- just that they can have
such a rule ... and that if/when you enter, you agree with their rules and
are bound by their rules. IOW, that's the entry fee. 

--
Martin