Karius gifted Real their first and third goals on the night with two calamitous errors and soon became the target of sinister personal abuse on social media by incensed so-called Liverpool 'fans'.
While the 24-year-old has received support from many fellow professionals and the majority of supporters, others wrote sickening messages to him on Twitter, including wishing 'aggressive terminal cancer' upon him and threats to murder his children.
Dear @TwitterSupport, please do a search for Loris Karius' account and the word 'die' and then delete every one of those bastards' accounts.— Dave Perkins (@SuffolkDave) May 26, 2018
A Merseyside Police spokesperson told the Daily Telegraph, "The force takes social media posts of this nature extremely seriously and any offences identified will be investigated.
"Merseyside Police would like to remind social media users that any offences including malicious communications and threatening behaviour will be investigated."
Since the final, a distraught Karius has personally addressed fans to apologise.
Taking to social media on Sunday, he wrote, "Haven't really slept until now... the scenes are still running through my head again and again... I'm infinitely sorry to my teammates, for you fans, and for all the staff. I know that I messed it up with the two mistakes and let you all down...
"..As I said I'd just like to turn back the time but that's not possible. It's even worse as we all felt that we could have beaten Real Madrid and we were in the game for a long time..."
Liverpool have already been tipped to search for a new starting goalkeeper this summer. Roma's Alisson, AC Milan's Gianluigi Donnarumma and departing Juventus legend Gianluigi Buffon have all been talked about as potential targets.