Council Tax & the HIMO

I am a landlord.

My property was originally occupied by a Man & Wife, who separated. They asked for separate tenancy agreements & now pay their own rent each.

I have now received a letter from the Council saying that the property is a HIMO & as such I must pay the Council tax.

I contacted the council to say that the tenancy agreement states the tenant is responsible & I believe the tenants were in the process of claiming benefits.

To which I was told that in the case of HIMOS, the Landlord has to pay & collect from the tenants.

Is this correct?

As they are both claiming benefits I thought they were entitled to Council Tax Benefit?

Any help would be appreciated