Simple, easy to use and powerful shell script. That detects same file with same hash and removes one of them.

rm_multi_files.sh

#!/bin/bash

# The script will detect copy files from current directory (sha512hash) and remove copy ones with prompt.
# Usage: ./rm_multi_files.sh

files=$(ls -1)
files_count=$(ls -1 | wc -l)

echo "Total files: $files_count"
# echo "Files: $files"

# Loop through files count
for ((i = 1; i < $files_count; i++)); do
    # Get file name
    file_1=$(echo "$files" | sed -n "$i"p)
    if [ -f "$file_1" ]; then
        # Get file hash
        file_1_hash=$(sha512sum "$file_1" | awk '{print $1}')
        # Loop through files count
        for ((j = i + 1; j < $files_count; j++)); do
            # Get file name
            file_2=$(echo "$files" | sed -n "$j"p)
            if [ -f "$file_2" ]; then
                # Get file hash
                file_2_hash=$(sha512sum "$file_2" | awk '{print $1}')
                # Check if file hash is same
                if [ "$file_1_hash" == "$file_2_hash" ]; then
                    echo $file_1_hash $file_2_hash
                    # user prompt
                    echo "file_1 : $file_1"
                    echo "file_2 : $file_2"
                    echo "Are same. Please press 1 for deleting file_1 and 2 for file_2(2) also you can (p)ass or (e)xit ? (1/2/p/e)"
                    read -r answer
                    if [ "$answer" == "1" ]; then
                        echo "Removing $file_1"
                        rm "$file_1"
                    elif [ "$answer" == "2" ]; then
                        echo "Removing $file_1"
                        rm "$file_1"
                    elif [ "$answer" == "p" ]; then
                        continue
                    else
                        exit
                    fi
                fi
            fi
        done
    fi
done