In the introduction to her book, The Silent State, Heather Brooke describes herself as a ‘nosey parker’. Whereas some people can’t walk past a curtain without needing to twitch it, Brooke has a yearning to poke around into the lives of those authority figures in public service, just to make sure everything that they’re doing is in the best interests of that public they are employed to serve. Over the course of a five-year investigation, she discovered that many of them were coming up short. In general parlance, this is commonly known as the ‘expenses scandal’.

‘I’ve got a really strange personality,’ Brooke confesses. ‘I don’t actually like getting into trouble and get anxious about it but I just can’t stop myself from asking awkward questions. I don’t realise at the time that they’re going to be awkward or uncomfortable but pretty quickly I get the impression that those questions are annoying people and then I have to decide whether to carry on or not.’ Her decision to keep on snooping into the financial affairs within the House of Commons was not popular with MPs and the Speaker, Michael Martin, who blocked every avenue she wished to go down, whether it was travel expenses, second homes or extra staff.

When the battle went legal, the High Court ruled in favour of Brooke in May 2008 and by the following summer, all hell had broken loose in the press and within the corridors of power. It even led to a BBC dramatisation of her campaign entitled On Expenses, with Brooke played by Anna Maxwell Martin. ‘It was great, it got me some recognition and was a great introduction to what I was doing,’ says Brooke. ‘Of course, it wasn’t totally word for word what was happening and my husband was more supportive than he was portrayed in the film.’

Born in Pennsylvania to Liverpudlian parents, Brooke worked on student newspapers before finally becoming a crime reporter. Her move to the UK occurred in 1997, a landmark moment in British politics with Tony Blair’s New Labour administration sweeping away years of Tory rule. The country seemed to have a fresh optimism but even before the Iraq War heralded a loss of mass faith, Brooke and others had seen the light. The UK state had turned into the most vigilant in Europe with CCTV cameras popping up everywhere (there are around 1.4m in public spaces), information databases infiltrating everyone’s lives and ID cards being lauded as some kind of social panacea while the government’s trumpeting of freedom of information seemed like a sick joke.

‘In the book I say that this surveillance is a symptom of our welfare state, as we have looked to the state to solve our problems,’ insists Brooke. ‘When you go back to the Bulger case, that was probably the first time CCTV was used in that way and it then became the magic bullet that authorities turned to so they wouldn’t have to actually get to the roots of social problems and crime. They could just get some cameras out to give the appearance that they were doing something.’

While Brooke doesn’t necessarily believe there was anything wholly sinister about the motivation of the politicians and civil servants who went along with this surveillance culture, she believes they exploited the essentially good nature of the British public. ‘There is an issue in Britain where the people had a very trusting relationship with authority whereas elsewhere in Europe they don’t because they’ve seen what happens when you put a blind trust in authority. I felt this lamb-like trust in politicians was strange when I first came to live in Britain. I would see the CCTV cameras and I’d want to hear the evidence to back them up. People thought they were a good thing simply because they’d been told that.’

Meanwhile, Brooke was informed that she had destroyed trust in British democracy. ‘That showed a complete misunderstanding about what democracy is. All I did was expose what other people were doing. The assumption there was that it was fine if they were committing crimes or abusing public money; the problem was the public knowing about it.’

Heather Brooke, Charlotte Square Gardens, 0845 373 5888, 21 Aug, noon, £10 (£8).