def remove_duplicate_tweets(tweets):
    """
    This function removes the duplicate tweets (if scraped by the twitter api), and returns all the unique tweets found in the current batch along with last tweet id.
    """
    seen_tweets = set()
    unique_tweets = []
    for tweet in tweets:
        if tweet.id not in seen_tweets:
            unique_tweets.append(tweet)
            seen_tweets.add(tweet.id)
    return unique_tweets