Injector hose question

Hello again!

After changing the fuel filter today I went for a drive and when I came back and parked up I could smell diesel and there was a lot of smoke. I popped the hood and saw diesel all over the engine bay.
The culprit was the blue hose in the attached photo. It had popped off, I've put it back on but it isn't very secure. It looks like a homemade replacement, I just want to know if it has been used to bypass something.
It just appears to be a drain from the injectors back to the fuel pump.

Thanks

looks like a bodge repair,
mine has a pipe there but secure and neatly fastened away not waving all over the engine bay

Get a little pipe clip on it and it will be fine - its the spill return for the injectors; they are usually just push fit as there is not any real pressure so its probably the pipe is too large an internal diameter or isn't very elastic and not holding itself on well.

Get some 4mm pipe from a local car spares shop.
Sold by the metre for £1 or 2

Thanks for the replies.
I used the hose already in the engine bay, just cut it a bit shorter and picked up a wee hose clip from the local garage for 20p, seems to be holding so far!