Double British Press Award-winner Sheila McNulty said that careful nurturing of contacts was essential in lifting the lid on BP's maintenance blunders that led to a huge Alaskan oil spill.
Her investigation into safety and environmental negligence at BP has led to a criminal inquiry and last week landed McNulty, the Financial Times'
US energy correspondent, two of British journalism's most prestigious prizes — reporter of the year and specialist writer of the year.
McNulty's inquiries into BP began in August 2002, coincidentally shortly after the FT ran a profile celebrating the head of BP, Lord John Brown, as one of the most respected CEOs.
McNulty received a tip-off from oil industry watchdog Chuck Hamel asking why the FT had profiled Brown, alerting her to major safety issues in Alaska.
Just two or three days later a BP worker in Alaska was thrown in the air and received burns all over his body after an oil well blew up.
Houston-based McNulty immediately began investigating the case. She said: "When I began asking questions, the workers told me BP had started this well without following the proper channels and had taken shortcuts before putting the well back into service.
Different workers would come to me through Chuck Hamel, although most of them were anonymous.
"It was really difficult to get them to come forward but some eventually went on the record. They were really afraid because there is a culture of fear within BP that if you make a complaint, especially a public complaint, you will be punished for it.
"After investigating BP, the Chemical Safety Board urged it to remove the fear of reporting of problems within the organisation and the fear of reprisal.
"I had to talk to the workers a lot on background and check out the information they gave me.
"I was always trying to get documents or information to back it up. My contacts started to respect the way we took great pains to make sure we got the facts right and began to trust us more as well."
Over a long period the FT reported numerous problems in Alaska as well as further accusations, but BP always issued "flat out denials" while company PRs told McNulty they had already investigated complaints and that she was pursuing a problem that wasn't there. When BP had another accident in Texas City in 2005 the rest of the media began to report the story.
McNulty said: "That proved it wasn't just little guys in Alaska complaining; they were making the same complaints that BP was under-funding, putting off maintenance, the equipment was run down and that the management didn't care about safety, so that was a real breakthrough.
"Then last year BP was responsible for the biggest oil spill on the Alaskan North Slope, with 267,000 gallons of crude oil discovered at Prudhoe Bayfield. The more I talked to workers in both places, the more it became evident this was really something big."
The Chemical Safety Board, the US federal agency investigating BP's accident in Texas, produced a report saying they suspected a safety issue within BP.
"The real breakthrough was when Lord Brown told a press conference the problems needed to be solved, it seemed like they were getting the message.
Brown then took early retirement and was replaced by Tony Hayward."
Although the Chemical Safety Board has finished its investigation, the FT obtained an internal email from BP Alaska's president Steve Marshall, revealing it had received a writ from the federal grand jury in Alaska. It will determine whether to bring charges against BP and/or its executives and could result in jail sentences.
McNulty discovered she wanted to be a journalist after contributing to the student paper at the University of Arizona, from where she holds a Bachelor's degree. It wasn't until she began contributing to her student paper that she discovered she had this ambition.
After travelling through Asia she returned to the States to work for the Associated Press in New Jersey, before moving with AP to Thailand. She covered political unrest in Cambodia and the UN's peace-keeping operation.
She later went to Dow Jones in New Jersey and was then in Malaysia as bureau chief before moving to the FT in 1997 in Malaysia, covering the Asian economic crisis as it was unfolding. In 2001 she moved to Houston to cover the energy and oil industry.