suspected abandonment of property next steps

[Tsink]

I believe that my tenants have abandoned my property and left the country 2 weeks ago. They had sublet to another couple who have still been accessing the property but not staying there. I have been advised by my agents (who only collect the rent which has not been fully paid since January) to give then a 3 day notice for inspection. I am a little concerned that they might just be away for their Easter (they are Romanian so likely Orthodox) but would obviously like to get my property back. Is there any guidance on doing inspectons at this time of social distancing so I can check if they are still there?
The neighbour is continually monitoring the comings and goings at the property.

[DPT57]

Have you served notice on your tenants at your property? As they are not living there you could serve a common law Notice To Quit alongside the usual s21. On expiry of the NTQ their tenancy should end, although I think you would then inherit the sub tenants as your tenants and have to evict them.

[mariner]

Don't accept any rent until resolved.

[Tsink]

DPT57,

Good news, they have now told me they have left the country and have left the keys.
Thank you for your reply.

[DPT57]

Great result. you dodged a bullet