DW: How did you first become aware that something was wrong in the Adekunle Fajuyi Estate, an upscale neighborhood in the heart of Lagos?

Toyosi Ogunseye: It just happened that one of the women from the estate fell ill [when she was in the UK], and a British doctor said she had a really rare form of cancer, which is usually only found in people living in a particular part of India who drink from a polluted river in a built-up industrial area. The woman's husband asked me to do a report - he just thought it was going to be a report, not an investigation. But when I went to the area, I realized I had a lot of work to do.

What did you find there?

I tried to talk to as many residents as possible and I noticed something really absurd. Every home had a child with a birth defect. I realized that this was really big, and I asked [the residents] if they would be willing to do some tests. They said yes, so we picked 30 people at random and did blood tests and urine tests. We also did water tests on wells and water from the ground. We had cases where the accepted level for cadmium [in the body] is about 0.001 milligrams and we had people who had 360 milligrams. It was that bad.

Nigeria is struggling to balance industrial growth with people's health

The evidence was clear, but still you faced a great many challenges in getting your story out. Describe some of the obstacles.

Of course the steel factory tried everything it could to stop the story coming out - money, inducement, calling colleagues to ask if they could put pressure on me. Even in the estate, there were people who were sympathetic to the company [Editor's note: owned by Universal Steels], because they were getting contracts from them.

How did the Nigerian government respond to your findings?

Initially they tried to cover it up. They have a pollution and environment agency which is situated just 15 minutes away from where this was taking place. It was right under their noses. Of course, the steel company paid money to the agency so there was some collusion. But it was quite difficult for them because we had scientific tests. If we hadn't had those tests, it would have been easier for them to rubbish my report.

Your report eventually resulted in the steel factory being shut down. Did you feel a sense of personal triumph?

No, that's not the most important thing for me. The most important thing is that I was able to make the people aware of [a problem] they didn't even know they had. The company is secondary. What's important is that the people realized that they were sick and were able to get treatment.

What advice would you give to investigative journalists working in a context in which they cannot trust the government to support their research?

You may want to reach out to NGOs to help you, for example with materials to do your research or with contacts. It could even be with getting you a reference from the hospital to say that you can do a test for free. In my case, I was very lucky because I had the support of my company [The Sunday Punch newspaper] because they offered to pay for all the tests - which is quite rare. Not all journalists are that lucky.