Every weekday evening about 30 million Brazilians tune in to one of the most popular TV chat shows in the world. You won't spot celebrities, however, on Ratinho Livre. Instead, you will see a parade of the grotesque - the deformed "elephant boy", the battered wife with punctured eyes, the woman whose hand was eaten by a dog, and the pregnant man.

For a show which was started only eight months ago, its success is unprecedented. It is all the more astonishing in a country where viewers have traditionally preferred to watch a non-stop diet of glamorous soap operas rather than programmes on the misfortune of the poor.

Ratinho says that his show functions like a court for people resigned to daily injustices. "People like to watch me because I am the only person who shows what Brazil is really like," says Carlos Massa, the 42-year-old presenter, whose nickname is Ratinho, or Mouse. (Ratinho Livre translates loosely as Mouse Unbound.) "I am the only person that shows that the justice system, the education system and the health system are failing for the majority of people in the country."

One top-rated show featured a woman whose jealous husband pierced her eyes with a needle and cut off part of her tongue and ears. Ratinho managed to get the Justice Minister to intervene and the husband was caught. Another had a feuding family that began bashing each other on the set. A bemused Ratinho let them fight, then waded in and took a couple of licks himself.

Weird diseases are a favourite theme, although they are all presented as appeals for medical help. When he presented, live on air, a picture of Elvis, a child with 21 tumours in his mouth, it caught the attention of top doctors. However, Elvis died in the ensuing surgery, causing Ratinho to burst into tears on air.

Another recent campaign was designed to get an operation for Brazil's "elephant boy" whose head is so deformed that Ratinho at first only showed him in profile through a screen - to spare the audience from the revulsion and the boy from embarrassment.

After this debut, however, his face was broadcast together with a computer generated image of what he could look like after plastic surgery. The parents, who are first cousins and have another son with a similar condition, burst into tears in front of the studio audience.

Ratinho - who improvises during the live show, bantering with the audience, brandishing a truncheon at the camera while the audience cheers and whistles - says there are no limits to what he will put on the programme. "The only criterion we use is that we try not to have people who have uncurable diseases," he says. "That doesn't make good television."

So what of the pregnant man? "He was really convinced he was pregnant. But he had some serious psychological problems," Ratinho concedes. "Now we're taking care of his treatment."

The show has made Ratinho, who comes from a poor family in the south of Brazil, one of Brazil's best-paid celebrities. He makes about £1.2 million sterling a year, although he makes the same again from betting phone lines that he encourages people to call during the programme.

He graduated from local radio to being a reporter on a TV true crime show before he was poached by TV Record, a small channel owned by the evangelist Protestants, the Universal Church of the Kingdom of God. His is the channel's most successful programme and is now the most watched show on weekday evenings, once the novellas on the other channels finish.

The audience of Ratinho Livre is predominantly poor Brazilians, although it is gaining a cult following among the middle classes. It is now a national institution. Several hundred people turn up at the Record studio headquarters every day wanting to go on the programme. Recently a computerised selection procedure was installed, which is open from 6 a.m. to 10 p.m. every weekday .

Last week the queue was round the block with people who had come from all over the country. Jose Antonio da Silva was there because his ex-wife had sold his house and car without his knowledge. He wanted to go on TV to try to persuade her to give them back.

"I want everyone to know what she did to me," he said. "I'm sure she'll come on the show to defend herself. Then there might be a big fight. This is the new way to get justice done in Brazil"