Some time ago, I wrote 2 letters to the police and another law enforcement agency, and I emailed a copy of both to my ex-boyfriend for him to check if he thought they were ok. I was alerting them about an aunt being mistreated by a cousin. They contained allegations and opinions expressed by myself, my aunt and my ex-boyfriend, but I signed them. The point of them was to try and help and protect my aunt. I wasn't just making malicious statements. Unfortunately, my ex-boyfriend turned on me later, and I believe he sent a copy of one or both of those letters to the cousin. I suspect the cousin will sue for defamation because he is complaining about his reputation being ruined. I'm not sure if he means because the authorities were notified or because my ex-boyfriend was, but nobody else saw the content of those letters. Are any defences available to me?