To highlight the plight of Indian students, the programme spoke to the family of student Prabmeet Singh, who had spent over $40,000 on a course at the Sydney flying school Aerospace Aviation.

His mother Pushpinder Kaur said the family was now broke and her son still did not have the pilot's licence.

'It is a fraud. We were shown so many rosy pictures about the school and it is not what it is really, it was just a scam,' Kaur was quoted as saying.

'I think the government should be more alert in these type of matters because it is the career of the children which is at stake.'

Other Indian students have told the Four Corners programme that the aviation college failed to deliver its promised 200 hours of flying time over 52 weeks.

Aerospace Aviation's spokeswoman Sue Davis has defended the training and has questioned the level of commitment and dedication among the affected students, the report said.

The programme also revealed unscrupulous practices by migration and education agents.

Karl Konrad, an education and migration agent based in Sydney, says he has been aware of a black market in dodgy documents for years.

'I had many students come to my offices and say, 'oh I can buy letters for $3,000 at particular restaurants',' he was quoted as saying by ABC online.

'They didn't name the restaurants, but I was getting many of these type of stories. (So) we sent that information to the Immigration Department and they in turn thanked us for the information and said they would pass it on to Trades Recognition Australia. Nothing ever became of that.'

The journalistic investigation followed the spate of attacks on Indian students, which also prompted the students to take out rallies to protest the muggings and assaults on them.

Authorities said that Indians were the victims of crime because they were more likely than others to be travelling late at night on public transport.

Australia has pulled in many Indian students with its offer of permanent residency for those who gain diplomas in vocational subjects.

But then, due to the economic downturn, the government in December made it more difficult for those with vocational qualifications to become permanent residents.

Monash University demographer Bob Birrell, who has campaigned against linking diplomas with visas, has warned of a backlash from Indian students who feel they have been duped by the Australian government now that visas are harder to get.

'It's unlikely they are going to leave Australia without a fight,' he told DPA.