from typing import List


def find_duplicate_movies(filename: str) -> List[str]:
    """
    Finds the duplicate movie titles from the given file.
    :param filename: str
    :return: list[str]
    """
    with open(filename) as f:
        movies = f.readlines()

    seen = set()
    duplicates = []
    for movie in movies:
        movie = movie.strip().lower()
        if movie in seen:
            duplicates.append(movie)
        seen.add(movie)
    return duplicates