Strange Light Leaks, Ilford HP5

[winger]

It could still be the camera if you shot much of the roll in darker situations than the affected section.

 

[250swb]

There seems to be far too much certainty that it isn't the camera, especially from the OP, and it's a bad idea to dismiss all avenues.

I have come across a similar leak before, top of negative on the edge and spilling onto the film area, which means any potential leak is coming in around the bottom of the camera. What somebody had done (not me honest) was to use either a tripod head or some accessory with a screw so long it had effectively punched out the steel tripod socket from the baseplate causing a crack to appear. Given the tripod socket is at the same end that the film is wound onto and outside the cassette something similar may or may not be a potential cause. So even if the OP has never used a tripod or accessory it would be worth inspecting the baseplate to look for cracks.

Steve

 

[AgX]

In case there are more films of that batch:

develop a unexposed film and compare it to a sample exposed in that camera.

(In case you do not want to sacrifice a whole film, cut out a snippet of the respective section and develop it unexposed.)