ExH and issues with DD

[namechange1984]

Posting here for traffic but more WWYD. Quick back story, married 10 years, problems with alcohol that got a lot worse after DD was born, which is the main reason I left. DD is nearly 4. He is on anti-depressants, but still drinking as far as I know. Nisi came through in June so all still new. He has DD EOW (Saturday/Sunday) but I made it very very very clear no alcohol to be consume when he has DD.
Nursery told me today that DD said I'm sad when daddy hits me. I have no idea what to do. Do kids say stuff like this or do I need to go in heavy with XH? No overnights etc...
Not sure how to handle it and obviously very concerned for DD safety.

He says he didn't (and has never hit her) but clearly there is something going on. DD called him on video call yesterday and she was chatting then said "daddy I don't like it when u smack me", he said I don't. DD said "no last time, like last time". Please bear in mind I have not mentioned it to DD since the day I heard from nursery so not like we have been talking about in everyday. DD obviously meant last time she was at his, but my mum senses are on full alert and I am meeting him face to face this Saturday to discuss it, so not sure what's going on still.