There were not many people packed in to the Los Angeles "town hall" meeting who had heard of the foreign woman with the unfamiliar title who had come to listen to their tales of plight. But many took it as a good sign that she had worried the last American government enough for it to keep her out of the country.

Deanne Weakly was among the first to the microphone. The 51-year-old estate agent told how a couple of years ago she was pulling in $80,000 (£48,000) a year from commissions selling homes in LA's booming property market.

When the bottom fell out of the business with the foreclosure crisis, she lost her own house and ended up living on the streets in a city with more homeless than any other in America. She was sexually assaulted, harassed by the police and in despair.

She turned to the city and California state governments for help. "No one wanted to listen. They blame you for being homeless in the first place," she said.

Others followed, recounting in English or Spanish, sometimes Korean, their personal crises. Some shouted their anger, others laboriously recounted details of losing homes, families forced into overcrowded shelters, life on the streets.

The United Nations special rapporteur, Raquel Rolnik, listened to it all patiently, occasionally taking notes, nodding encouragement.

Rolnik had waited more than a year to tour cities across the US to prepare a report for the UN's human rights council on America's deepening housing crisis following the subprime mortgage debacle.

UN special rapporteurs are more often found investigating human rights in Sudan and Burundi or abuses of the Israeli occupation than exposing the underbelly of the American dream. George Bush's administration blocked her visit, finding itself in the company of Cuba, Burma and North Korea in blocking a special rapporteur.

"I was asking for almost a year before I as allowed in," Rolnik said.

When Barack Obama came to power she was welcomed to range across America talking to those who have lived on the streets for years and the newly homeless forced out by the foreclosure crisis.

Rolnik, a Brazilian urban planner and architect, said administration officials were genuinely interested in what she might find, if not embracing of her raison d'etre that everyone is entitled to a decent home.

"One of the first meetings I had at the state department they clearly told me: here, adequate housing is not a human right," she said.

"I was shocked when I realised that the US, and countries in Europe – England – as well, had a solid housing policy for many years that worked pretty well. That was dismantled and the situation became worse throughout the nineties. Then we had this financial crisis and a real crisis in housing. It's all tied together," she said.

"But I didn't expect to see what I have seen. In some ways the situation is worse than I expected."

Rolnik travelled from New York and Chicago to New Orleans and South Dakota's Native American reservations, talking to the homeless, the desperate, the foreclosed, and the officials who run housing policy.

Her final stop was Los Angeles, the homeless capital of the nation. Up to 100,000 people are sleeping on the streets or in shelters on any given night. Some have been living like that for years. Others found themselves suddenly destitute as the bank seized their home or they lost a job and couldn't pay the rent.

Two years ago about 1,300 people were evicted from properties in central LA. Last year it was 15,500. Across the wider Los Angeles region 62,400 people were thrown out of their homes.

"There is a predictable path for those who lose their jobs and can't pay the rent or the mortgage," Gary Blasi, a University of California law professor, told Rolnik. "First they live with friends and relatives, but they're poor, too. Then they live in their cars until the cars get towed or break down. Some live in tents. Almost all the camping grounds within 100 miles of Los Angeles are now filled with people living in them."

A single person on welfare living in Los Angeles receives $221 a month – an amount that hasn't changed in a decade. The rent for one room is typically nearly double that. Too often the newly destitute end up on the streets.

"I had a job as a cashier in K-Mart and shared a house with other women," Deborah Burton told Rolnik. "But then I lost my job and when you lose your job you lose your home. You can't pay the rent."

Burton, 57, found herself sleeping on the streets. She explained how the tents go up on Skid Row in central LA after dark but must be down before dawn.

"If you aren't up and moving by 6am, the police arrest you for sleeping or sitting on the sidewalk. It goes on your record and makes it very difficult to get [public] housing," she said. "Not many think of us as people. Don't criminalise us because we find ourselves in a certain situation. No one wants to be homeless."

Doris Tinson certainly doesn't but she is on the brink of losing the house she bought in 1964 for $29,000. She paid off the mortgage several times as she borrowed against the house to supplement her pay as a nurse and send her children, and then grandchildren, to college.

Then a few years ago, a man came knocking offering her a cheap mortgage, a fraction of the value of the house by then put at $750,000. Tinson took out the $87,000 loan but along the way the monthly payments quadrupled to $2,324, nearly her entire income and they are set to rise again.

"The mortgage went up because the interest rate went up. I still don't know how that happened," she told Rolnik.

On Los Angeles' own Wall Street, in the poorer, mostly black and Hispanic, south of the city, the "for sale" signs hang outside the boarded and secured foreclosed homes with warning notices against trespass. On average homes have lost two-thirds of their value in south central LA.

At the end of 2008 about 2% of Los Angeles homes had been foreclosed on. Housing activists told Rolnik that was mostly because of sharply increasing unemployment and predatory lending that exploited the vulnerable.

Rolnik takes it all in. Later she describes herself as disturbed that a country so rich is in many ways so deficient and indifferent in dealing with its poor and vulnerable.

She says that the more recent conservative philosophy of dismantling the old policy of providing affordable housing to those with smaller incomes in favour of the illusion that everyone can, and should, buy their own home played a central role in not only creating the housing crisis but the financial one.

"Part of the financial crisis has to do with these housing policy options because one of the main ideas of this policy is to promote home ownership to those who never got access to property. People who never had credit finally had banks provide them credit and they can buy a home. But it didn't work for the poor.

"So now we have a new face of homelessness – people who had homes, were not living in public housing, were not living in assisted housing, but now are in a position of asking for assistance because they're homeless. But the public housing has been destroyed," she said.

Rolnik held a town hall meeting in every city she had visited. Always they were packed.

At the Los Angeles meeting, the queues quickly form at the three microphones.

Toni Matthews has been homeless for nearly nine years. "I wrote to Washington but nobody ever answered," she said.

A Spanish-speaking veteran of the Korean war steps up. He is the angriest of the lot. He is not a communist, he says, but in Cuba nobody goes homeless. He fought for America and now he is left to live on the streets.

Others tell of being evicted by unscrupulous landlords, of living in dangerous and filthy buildings and how the city council doesn't force landlords to obey the law. The frustration is mixed with a sense of powerlessness.

"Anyone can end up in this situation, living on the streets. Don't imagine it can't happen to any of you," shouted a man.

Away from the microphone, Deanne Weakly says she had never heard of a UN special rapporteur but she's glad Rolnik turned up.

"I am grateful for the spotlight on the homeless. The spotlight of attention on what people don't think exists here. These people have no voice. They're afraid. Not everyone has a big mouth like me," she said.

Deborah Burton thinks it is a shameful reflection on America that Rolnik should be in the US.

"America is one of the richest countries in the world. For me as a citizen and a person of colour I think it's important to let the rest of the world know what's going on here," she said.

"American politicians come and listen but they don't do anything. The question we have to answer is why this has been going on so long."

Rolnik doesn't pretend she can change the situation. All she can do, she tells the crowd at the meeting, is to draw their problems to the attention of their government and warn others of the dangers.

"The US has exported an economic model with the idea that everyone can organise themselves under that model. It's very important for the rest of the world to know who fits in to this model and who is excluded," she tells her audience.