Protected / Sitting Tenant - arrears – property access / copy of keys - fraud -misuse of

Tenancy Types and Management

We have a protected / sitting tenant who has resided in the building for over 30 years though we have owned it for the past 26.

She has been a problematic tenant since the beginning and before us with the previous owners as well.

We have sought help from the tenancy relations officer and other members of the council regarding our issues with the tenant though it seems that landlords do not get help in these situations by a council that do not want the responsibility of dealing with tenants such as this.

At present we have the following problems which we would be grateful for any advice to remedy the situation or result in evicting the tenant.

Arrears

She has accumulated over £3000 worth of arrears as she on-goingly deducts a proportion of her rent for water rates. The rent is assessed by the fair rent commission every two years and is supposed to include all rates.
However, over 10 years ago we were converting her flat to have a self contained boiler as she was previously using the landlords supply. She refused this for many years claiming it would give her additional costs. In order to install we offered a reduction in her weekly rate to compensate for any additional costs. After many years of dispute the boiler was finally installed. The offer was not time specific and was not meant to be ongoing past the next rent review by the Fair Rent Officer who includes water rates into the fair rent. She has however continued to deduct this (though not accurately paying variable amounts). She claims that she is still entitled to deduct water rates. Is she right or can we commence proceedings against her and attempt eviction should the judgment go our way?

Restricted Communication

Since the beginning of her tenancy the tenant has been abusive, aggressive and on occasion violent when dealing with us and those we employ. We have subsequently decided to only correspond with her in writing and will not permit any direct personal contact with her except in emergency.
We believe she suffers from mental illness though unless we can state that we are concerned for her health and safety or those who come into contact with her the authorities refuse to take action or inspect the situation.
We have told her that should she be able to improve her behaviour toward us and provide us with adequate proof that she is making efforts to improve, we will resume normal communications again.
If there are any legal reasons why this is questionable please let us know.
She has also been attempting to charge us with harassment for many years, though to someone who is familiar with our case it more likely that the harassment is from the tenant.
Does our non personal correspondence aid her or us in this respect?

Keys

Many years ago the tenant had the locks changed on the flat. This was provided for her free of charge by the Metropolitan Police. We were not given a copy of the keys. In the light that we refuse any direct personal contact with her this effectively removes our ability to inspect the premises and creates a logistical problem when repairs or works are required.
Is it possible for us to force her to provide us with a copy of the keys?

Unconsented Alterations

The tenant is apparently 90 years old, certainly elderly (we are not sure of her true age or true name as she has been known under several pseudonyms and has an unknown history). She managed to get the Warm Front Team (a government run organization for helping the elderly) to undergo works in the Flat without our signed consent. We wanted to confirm the work would not damage any of the original period doors and windows before consenting. We have recently had problems with the sash windows possibly as result of this unconsented work. They claim however to never have carried out any work in the flat despite our tenant assuring us that they did. She will not provide us with any copies of correspondence with them despite our numerous requests.

The hard evidence we have is the original request of consent form, her letters at the time queering our delay in signing the consent form and her future correspondence stating the work was carried out vs. their email denying any work.
What action can we take against her or the Warmfront?

Gas Fireplace

The tenant has always refused us installing central heating on grounds that this will increase her living costs (again provided for her by government benefits) and that we are altering the property for once she has gone and not for her benefit.
At the end of 2005 we replaced her faulty gas heater with a power flue gas fireplace. The appliance was more economical with a higher heat output and certainly more aesthetically pleasing than the original gas heater. The tenant was present at estimates and involved as much as possible with the decision making process. 2-3 weeks later the appliance was inspected by British gas (landlords annual gas safety inspection) and found to be in good working order. Since that date she has claimed on numerous occasions that the appliance was not working properly though we are sure it was as we live directly below her and can hear the power flue working. She also admitted in writing to stuffing paper in the flue to avoid drafts.
She managed to get a British Gas engineer to visit the flat on a pretence about the boiler. A British Gas colleague of that engineer claimed that he was badgered and locked into the flat until he agreed to place a warning sign on the fireplace stating that it was unsafe as it is should not be installed in a room where someone sleeps (the tenant uses the sitting room as a bedroom and the bedroom as a storage room). This of course is untrue as the appliance conforms to regulations and is well within parameters to be used safely in a bedroom or sleeping area. The tenant contacted environmental health relating to this issue. British gas were invited to visit again in the presence of an Environmental Health Officer to inspect and revoke the warning that was placed by an employee that was unqualified to do so and furthermore was not booked for the specific job and thus against British Gas's own Guidelines.
British Gas was informed that a council officer would be present though they did not pass this information on to the engineer who visited.
The tenant claimed as witnessed by the Environmental Health Officer and the Engineer that 'smokey fumes' had been emitted from the fireplace and that the British Gas Engineer was 'removing evidence' when he attempted to remove soot that had settled around it.
The British Gas Engineer refused to continue as he did not want to be involved in a legal dispute and rejected not being informed of the councils presence.
We have since cancelled our contract with British Gas as they were unable to resolve the issue. Gas~Elec were subsequently contracted to inspect and service the gas fire though again refused to complete for similar reasons. They subsequently disconnected the gasfire.
The issue remains unresolved. Even with the fireplace disconnected there is adequate heating as far as landlords obligations are concerned. We are however eager to inspect the fireplace as we are concerned that the tenant has used it incorrectly/unsafely and has possibly damaged it. Please advise.

Fraud

The tenant claims full benefits though actively deducts money from her rent pocketing the remainder.
I know the tenant works as an artist selling her work at local galleries (£200-£300 per painting). I have even found sales of her work posted online by some of the galleries.
I suspect that she has several pseudonyms and may even be claiming more than once. I have filed anonymous fraud claims online (Department of Work and Pensions) but this seems to of had no result.
Are working O.A.P artists able to sell artwork without declaring this income?
Are there any other bodies I can report this to?
Is there any way I can have this further investigated?

Living status

I am currently overseeing the renovation of the family flat (where currently live) which is to be let in the near