SYDNEY, June 22 (Reuters) - An Australian cyber regulator on Thursday said it has demanded Twitter explain its handling of online hate as the microblog has become the country's most complained-about platform since new owner Elon Musk lifted bans on a reported 62,000 accounts. The demand builds on a campaign by the eSafety Commissioner to make the website more accountable after Musk, one of the world's richest people, bought it for $44 billion in October with a promise to restore its commitment to free speech. The regulator has already called on Twitter to detail its handling of online child abuse...