It looks thin and the colour of masonite.
Either way it doesn't contain asbestos so you can do as you please with it.

Thanks so much for replying. I don't think there is any joining strips. Its in basically one large piece/sheet in bathroom ceiling. Are these usually hard to remove and to…

In the first picture (link) you can see the joint. They've used a vee joint so I'd say it's either the canite or masonite. Both are timber fibre base so…

An option may be to leave ceiling material in place and glue and screw plasterboard under and then finish off and paint.

It looks like perforated Caneite judging by the texture, are there any joining strips?

looks like pegboard or perforated masonite, made from hardwood at heatherbrae