Free Throw Positioning....Top of the key ???

[WeekendRef]

Just a quick question . On a free throw do the players who are not in the lane required to stay above the top of the key extended (NFHS) ?
I had a situation this past weekend where a player lined up above the free throw line extended and behind the three point line but below the top of the key . I asked him to move beyond the top of the key extended (and of course to remain there till the ball hit the rim)and I caught some heat from the coach who said he had never heard that before.... I convinced him I was correct because I was almost 100 % certain I was . I will have him again tonight so I just want to be prepared because I know he will be . I just looked in my case book (Rule book is at home) and I didn't see anything that supported me.... (Whoops !) Any feedback is welcome .