It's common (for me) to hear that a HV power line can kill a person without touching it "if they entered its field." I'm not convinced by this reason and I think it quite naive and that it doesn't clarify anything.
Warning: Video shows people dying.
Video with information about the accident(longer than the YouTube version)
Here's a video of some workers killed by HV but it's not clear if the scaffold touched the line or just "entered the field of the lines."
Best Answer
Yes. The higher the voltage, the larger an air gap is needed to keep it from jumping or arcing between conductors. You, a wet fleshy human, can provide an ideal path between two high voltage conductors if you get in the middle. You do not need to touch one.
This is basically what allows lightning, Tesla coils, and Jacob's Ladders to exist.
As pointed out in the comments, the higher the voltage carried, the taller its transmission towers will be and the further each conductor will be from the others.