Can we file a criminal case against the guarantor?

I think you need to start with our:

Tenant Eviction page >> https://www.property118.com/evicting-tenants/

and

Private Prosecutions page >> https://www.property118.com/private-prosecutions/

Hi Sr Kot
Are you saying that the guarantor is renting your property to a new tenant? If so, your best and most immediate course of action is to contact the current occupiers (preferably in person or through an agent) and tell them that they are trespassers. What happens next depends on what you discover. If the tenants are mates of the guarantor and in collusion with him then you need to take immediate action to get them out and tell them that you will sue them for use of the property so they will pay double rent.

If they are innocent dupes, then you should explain what is going on, tell them to stop paying rent to the guarantor but instead to you. When the guarantor complains tell them to tell him to get in touch with you.

Subject to seeing the terms of the tenancy and to taking up references on them you may be happy to keep the tenants. If not, then evict them as before.

You describe it as a fraudulent tenancy. By a quirk of property law if L leases property to T that L does not own, it is still a lease and L can sue for rent. Provided T is not disturbed he receives what he has bargained for, namely possession and use of the property. However, if T is "lawfully dispossessed", i.e. the true owner comes along and boots out T, L is liable to T in damages. You as true owner may also be able to recover mesne (pronounced mean) profits for the use of the property from T.

G may be guilty of an offence (such as fraud by pretending to be the real owner) but I would not think about prosecution until you have sorted out the tenant first.

Do you have a UK agent? If not, get one. Otherwise you will struggle to deal with this matter.

How is this not straight up theft? The guarantor has illegally got the keys to someone else's property and is renting it out as if it was their own.

If I got keys to someone else's car, and took it as if it was my own, that's theft. What's the difference?

Reply to the comment left by "Colin McNulty" at "12/03/2017 - 14:19":

Like many things with property Colin.

I currently had a tenant go away five months ago not to return not paid rent in three months left full of his possessions. You would think I could just go in and sort it out and rent. No I have to put up with the lies and excuses. If not I can be prosecuted for harassment.

For some reason when it comes to let property theft is not theft.
Vandalism is not vandalism
Fraud is not fraud
Criminal damage is not criminal damage.
According to the police this is all civil matters. No it is not but you have to fight to get them to take action.

The law really needs to change.

Reply to the comment left by "Colin McNulty" at "12/03/2017 - 14:19":

Hi Colin
I am not defending the guarantor's action. The point is the criminal law does not always apply in cases like this. From whom has the guarantor stolen? Not the tenant who is enjoying the use of the property. Has the guarantor "illegally got the keys"? Probably not. The previous lawful tenant may have given them to him. Has he obtained property by deceiving the tenant? Yes, he may have but equally he may not have said anything to the tenant about owning the flat or being entitled to it. As Neil Robb has indicated the police are just not interested. Case such as this are complicated and they have limited resources.

I understand your point Ian but I look at it like this. If I hire a car for the weekend, and then at the end of the weekend, instead of giving it back, give you the keys and you drive off with it, the hire company would call the police and say you've stolen it. You have no right to the car. Just because I had the keys for the weekend, doesn't make it lawful for me to give them to you. You have taken someone else's property without their consent. That's the definition of theft.

Reply to the comment left by "Colin McNulty" at "14/03/2017 - 20:52":

Only just seen this comment Colin. I am afraid your analogy breaks down. The guarantor has not "driven off" in the house or removed it. Section 1 of the Theft Act 1968 says:

"A person is guilty of theft if he dishonestly appropriates property belonging to another with the intention of permanently depriving the other of it; and “thief” and “steal” shall be construed accordingly."

Section 4(2) of that Act says: "A person cannot steal land, or things forming part of land and severed from it by him or by his directions, except in the following cases, that it to say—
(a)when he is a trustee or personal representative, or is authorised by power of attorney, or as liquidator of a company, or otherwise, to sell or dispose of land belonging to another, and he appropriates the land or anything forming part of it by dealing with it in breach of the confidence reposed in him; or
(b)when he is not in possession of the land and appropriates anything forming part of the land by severing it or causing it to be severed, or after it has been severed; or
(c)when, being in possession of the land under a tenancy, he appropriates the whole or part of any fixture or structure let to be used with the land."

Thanks Ian. "A person cannot steal land" that's interesting.

So if I rent your house, then pretend to be you and "sell" it to an unsuspecting buyer, if that's not theft, what offence would I have committed against you? I'd assume I'd be guilty of fraud against the buyer, and/or their lender, but selling someone else's property must be caught by some offence too, no?

Reply to the comment left by "Colin McNulty" at "19/03/2017 - 06:18":

Why do you think this would not fall under (c) in the exceptions listed in Ian's post above?

Reply to the comment left by "Old Mrs Landlord" at "19/03/2017 - 07:46":

I am getting out of my comfort zone here as I am a property lawyer and don't practise criminal law.
However, exception (c) relates to removing a fixture or structure. For example, a house may have an Adam fireplace. It is part of the property and may be treated as "land" in English law. If it is removed and sold by a thief he cannot use s4(2) as a defence to say that because it is land, he cannot have stolen it. So the offence in Colin's example would not be prosecuted under the Theft Act but the Fraud Act 2006.