Slum conditions, overcrowding and dodgy landlords - welcome to foreign student accommodation in Australia's most glamorous city.

More than 350,000 foreign students are enrolled in colleges and universities around the country, and many are attracted to the charms of cosmopolitan Sydney.

But the tough reality of living in one of the world's great cities, with its spectacular harbour and famed beaches, can be very different to expectations.

Cheap accommodation is hard to find and rogue landlords entice students into their net with advertisements promising centrally-located quality apartments at reasonable prices.

When they turn up, the lodgings bear little resemblance to the promises.

"I visited this two-room apartment in Haymarket which looked fine in the pictures," said Alice Lala, a French student who studies at Sydney University.

"The problem was it was packed with 18 people, most of them students or on working-holiday visas. Those guys literally slept in boxes piled up on top of each other. For 120 dollars a week, I thought it was a joke."

Many students, though, have little choice but to rough it in overcrowded, shoddily converted family homes, unable to afford anything else.

Finding somewhere to stay in Sydney is tough, with the traditional influx of new student arrivals in February and July triggering an often astronomical rise in rents around universities as demand spikes.

Macquarie University, for example, has more than 12,000 students but fewer than 2,000 university-supported rooms. It is a similar scenario at the University of Sydney where 10,800 students compete for the 2,500 beds on campus.

"The main difficulty faced by all students in Sydney is the lack of affordable accommodation," said David Burrows, an accommodation officer at Sydney University.

"Most students have a budget of about $180-200 a week, yet the average price for a room near the university's main campus in the city is $220."

To make ends meet, foreign students often have to work at several jobs to pay their rent, doing night shifts in convenience stores and even lending their bodies for medical research.

"Overseas students are more vulnerable to predatory landlords," explained a spokeswoman for the Redfern Legal Centre, which provides assistance to students who fall victim to exploitative landlords.

"Most of the time, they arrange accommodation prior to arrival and because they might struggle with English they are not aware of their rights and just take what is offered."

Overcrowding

In the heart of central Sydney, 33 floors above fashionable Pitt Street, Matt is looking for people to share a tiny apartment he leases for Aus$700 (US$757) a week.

When AFP visited, he had just moved in and had already found two flatmates, one for the living room in a small space separated by a partition, and one for a bed on an enclosed balcony.

Four bunk beds were still available.

He wants Aus$135 a week for each bunk bed, Aus$115 for the living room spot, and Aus$150 for the enclosed balcony.

Altogether it will bring in Aus$805 dollars, meaning Matt and his girlfriend can live for free, with more than Aus$100 spending money each week.

Similar situations are common, despite sub-letting being illegal.

Traditionally, students have found slum-like flats advertised near universities on lampposts.

However, the website www.gumtree.com.au has emerged as an equally popular way to find a room or bed. But while honesty is the norm, scams and predators exist.

"The most common scams occur when students respond to false advertisements, created by people pretending to be landlords," said Burrows, the Sydney University official.

"The student is then scammed into sending money to secure a room, without yet having seen the accommodation available."

Sex for rent is another reality some students have to deal with.

Art student Hannah Tooley posted a 'wanted' ad on gumtree that read: "Four British girls searching for home close to Sydney Uni."

Within hours she received an answer: "Hi there, how are you? I am wondering if you would all be interested in 150 dollars an hour each cash in hand, by giving me a full body massage with hand relief?"

Redfern Legal Centre said it receives a variety of complaints, although sex for rent was not high on the list.

"The major problem is people being stripped of their bond," said the centre, with landlords sometimes refusing to return deposits.

"I definitely feel taken advantage of," said Brian Dawson, an American student whose landlord refused to hand back his Aus$580 bond.

"It is a hard lesson to learn when you are a student and money is so tight."

To avoid such scams, some students go through real estate agents, where contracts are clear and information reliable.

But the flipside is that agents usually insist on a six-to-12 month lease, a requirement that some overseas students cannot satisfy.

Backpacker hostels are another option. A bed in a dorm is not always cheaper than a shared flat, but no bond is required, and there are no bills.

However, hostels are forbidden by law to take bookings for more than 28 days, meaning students have to move from one to another.

Authorities have little power to curtail bad renting practices, according to Sydney Council.

"Council has very limited powers to investigate the problem and evidence is hard to gather as our compliance staff can only enter a residential home if they have consent of the owner or occupier," said a spokesperson.

This is highlighted by the low number of property owners taken to court -- just 15 between 2008 and 2010, council figures show.