Bella and Jimmy Browne bought the three-bedroomed terraced house opposite their home in North London in 1958 as an investment for their old age. Jimmy has since died, but Bella, now 77, continues to let the three bedsits against the wishes of her son, who has begged her to sell the house.

He says: "She used to have student nurses as tenants and then she had a series of students, who were OK, except for a party which caused a lot of damage. Things started to go wrong in the mid-Eighties, and recently she has had rogue after rogue. When she asks for the rent, they tell her to eff off. She only charges pounds 40 a week, including electricity and central heating, and she mows the lawn and keeps the house in good repair. She put in two pay phones but they were ripped off the wall for the cash box.

"To me it's been a total nightmare. In the past, she let rooms to ordinary working men who would knock on her door with the rent every week, but now she gets people who have no intention of paying. They pay for a couple of weeks, then stop. Of her most recent tenants, only one had paid his rent regularly. It amazes me that people who are in work and could pay rent, prefer to exploit an old lady. Mum worked as a bus conductor until she retired, and she still does a part-time cleaning job.

"She has two tenants at the moment who haven't paid rent since December. I took them to a county court and the judge gave them 28 days to pay their arrears. At the end of the month, if they haven't paid up, I'll get the bailiffs in to get them out, but it has all taken time and money. It costs about pounds 500 to get someone out, and you are lucky if they don't trash the place before they go.

"Mum has had a number of tenants who have become unemployed and got housing benefit, but we weren't told, and the money wasn't sent to us. We discovered two of the tenants were claiming more in housing benefit than they paid in rent, but when I complained, the council said its paramount duty was to protect tenants' privacy. They didn't prosecute.

"Mum has just one tenant who is as good as gold, and who has been with her for years. She is worried he will be homeless if she sells the house. I suggested she should give him a spare room in her own house. She already launders his sheets every week and thinks of him as part of the family. It's a shame to pull out of letting, because single people need homes. But who is going to risk taking them on when there are all these people exploiting the system, not paying rent, staying as long as they can and then moving on to cause trouble somewhere else?

"I would like to see special tenancy courts set up, which would deal quickly with disputes. At the moment, it can take two or three months to get a date for a county court, and you can't take successful action against tenants until they are 13 weeks in arrears. Then, if they have paid some of it off, and claim they can't afford to pay more, they are usually given three months to try to sort themselves out. Months pass, and the landlord isn't receiving a penny."