Strange stains after washing

[jjabrams]

Hi, i'm really lost so hope mumsnet can help. I've washed my sons clothes and they grey/white ones have come out the washing machine more stained than when they went in. It's a kind of rust colored stain and i have no idea where it came from. I've tried everything to get it out and nothing works. Any ideas would be greatly appreciated.

I've attached some images: imgur.com/a/lWAaKLI

I had a quick google. This might help? dengarden.com/cleaning/What-Causes-Those-Stains-on-Your-Clothes-Mystery-Stains-That-Appear-Only-After-Washing

Thank-you, unfortunately that didn't seem to help and none of the usual home remedies are working. I thought because the stains are rust coloured it could be to do with rust so i've got some rust fabric remover in the hopes that works.

I keep having issues with stains on clothing!
Only my partners clothes though so must be something specific to him
No idea what as they are in random places on his t shirts?!?!?
Bizarre

I had this problem. Was using Ecover laundry liquid. Switched to biological washing powder and have never had a problem since !

I get random pink stains on towels and tracksuit bottoms and t shirts. Does anyone know why please as it drives me mad.
No one colouring hair etc, the towels are just grubby when they go in the washing machine not stained. It’s usually always grey towels and grey clothes that are affected.
Use fairy liquid detergent non bio and fairy fabric softener.
Thanks for any clues.