@Santanu0
What you are describing is possibly a little bit different. The guest was prepared to cooperate with Airbnb.
At times guests do take liberties where check-out is concerned and if possible we do have to be a bit flexible. Once you involve Airbnb to get the guest to leave you will almost certainly get a bad review......and with only 5 reviews behind you Santanu, a bad review is something you should try to avoid.
What @Ana246 was describing back in 2016 was the fact that an Airbnb guest had taken 'possession' of her property and had no intention of relinquishing it until they were ready. It obviously resolved itself because she unfortunately did not come back here to tell us of the outcome!
We have heard of this before, the guest goes to a local hardware and change the locks thereby precluding the host from gaining access to his/her property.
In most instances police will not want to get involved because it is deemed to be a civil matter and not one that requires police attendance. Situations like that are difficult and it's a pity that authorities do not seem to regard trespass as....trespass, removal from the property is something that the court system will get around to in the fullness of time....and that can break a landlord!
Cheers.......Rob