In December 2019, Malta’s PM Joseph Muscat resigned, driven from office by the constitutional and political crisis triggered by the murder of the investigative journalist Daphne Caruana Galizia. Here, we talk to the Guardian’s investigative reporter Juliette Garside about her role in exposing the truth about what happened.

What was your first encounter with Daphne Caruana Galizia?

I had gone to Malta before Daphne was killed, to report on some of the political controversies she was exposing. She was Malta’s most famous journalist, working on very important stories, and we were worried she was isolated. Her son got in touch asking us to provide some support, and I went out just before the general election. We only wish we could have done more. There are big social and governmental issues in Malta and its news outlets often require patronage from one party or another, but Daphne had alienated both through her work, leaving her exposed. She was hugely effective and she asked the big questions. She wanted to call out her country’s dysfunctional electoral system, financial regulators and money laundering, and ask how a European nation like hers was able to operate like this without consequences.

Facebook Twitter Pinterest Juliette Garside at her desk in the Guardian’s London offices. Photograph: Graeme Robertson/The Guardian

How did the investigation unfold?

The first instalment of our Daphne Project was published in April 2018, six months after she was killed in a car bomb. We were a loose collective of journalists, from Reuters, the Times of Malta, Le Monde and Süddeutsche Zeitung, who had agreed to work together. The idea for the collaboration came from Laurent Richard, the Paris documentary maker. He had just set up the Forbidden Stories network, whose mission is to continue the work of reporters who have been silenced in some way, either through violence, incarceration, or in Daphne’s case, murder. Our stories focused on the police investigation, but also on concerns about corruption in political and business circles. I had been given a copy of a big leak of data from a flagship power station project. Daphne had been receiving the data when she was killed. She hadn’t had time to look at it. We found secret information showing this power station was a really bad deal for Malta, with taxpayers losing money hand over fist.

In October 2018, a year after the killing, we published another round of articles. The most important of these was about 17 Black Limited, a mysterious shell company Daphne had been looking into just before her death. Emails showed other shell companies in Panama, belonging to the energy minister and a second key member of the government, were due to receive payments from 17 Black. But nobody knew who it belonged to. Reuters revealed that the owner was businessman Yorgen Fenech, who also owned the power station.

Facebook Twitter Pinterest Matthew Caruana Galizia (left) and Paul Caruana Galizia, the sons of the murdered Maltese journalist Daphne Caruana Galizia, attend a vigil outside the Maltese high commission in London, six months after she was assassinated. Photograph: Tolga Akmen/AFP via Getty Images

The police had arrested the alleged bombers, who are awaiting trial. But the investigation into who had commissioned the killing had stalled. Two years later, the mastermind was still at large.

Finally, in November 2019, a middleman was arrested, and he began to talk. After receiving a presidential pardon in return for information, he named Fenech as the person who had paid for the assassination. Fenech was arrested while trying to flee Malta on board his yacht. He denies accusations of complicity in the killing. Soon after his arrest, we saw the resignations of the two cabinet members who had allegedly been due to receive payments from 17 Black: the former energy minister Konrad Mizzi and the prime minister’s chief of staff Keith Schembri. They both deny wrongdoing. By this point, the world’s media had turned to the story.

What was your main role in the coverage of this story?

Prior to joining the investigations team, I worked as a business reporter. My specialism is financial reporting, especially stories involving tax dodging and money laundering. I have a good knowledge of law and business, and am able to take a forensic look at financial accounts and money trails and help comb through big data sets. It’s often rather exhausting and painstaking work, and the kind of stories we unearth are legally risky, but it’s important in painting a clear picture of events.

Who else was involved in covering this?

Jacob Borg, from the Times of Malta, did some incredible on-the-ground reporting. He got a tipoff and was down at the marina watching last November as Fenech tried to flee the country on his yacht – his boat was stopped and the police brought him back onshore. Stephen Grey at Reuters was key to the 17 Black investigation - a real “shoe leather journalist”, as they say - as were Daphne’s sons Matthew (a computer programmer and investigative journalist) and Paul (also a journalist). Carlo Bonini from the Italian newspaper la Repubblica was also great in terms of police contacts. And of course my Guardian colleagues Hilary Osborne and David Pegg, my editor Nick Hopkins, and our Washington investigations correspondent Stephanie Kirchgaessner. It was Stephanie who arranged for us to get the data about the power station from Daphne’s sons.

Why was the Guardian well placed to cover this story?

The Guardian is a platform with a big readership, which can provide the much-needed rocket fuel for a story like this, but it can’t be emphasised enough how much of a collaborative effort was required to get it off the ground. One of the things that sets us apart from many other media groups, though, is the lack of a paywall, which means we are very widely read. And we publish in English, which gives us a huge potential readership. Our readers care about these sorts of stories. We have a long history of covering tax dodgers, corruption and kleptocrats with murky pasts. There’s our investigative work into HSBC’s Swiss bank, Apple, the Chinese retail industry, and of course the Panama and Paradise Papers, which had huge ripple effects. It’s an area we want to keep well-resourced.

Has Daphne’s death triggered change in Malta?

One impact was the resignation of Joseph Muscat as prime minister. His Labour party are still in power, and he has been replaced by Robert Abela, who was very much seen as the continuity candidate. People don’t think he will prosecute the alleged corruption cases uncovered during this affair. With Fenech due to stand trial, it’s possible that individuals closer to Muscat could be implicated, so who knows what that will bring.

Perhaps more importantly, Europe has woken up to the dangers that corruption in Malta represents for rule of law in the EU. And we are seeing the beginnings of a civil society in Malta; citizens are feeling more empowered. It’s so important for the family that this story continues to be covered. Nobody has been convicted of the murder yet, and the political corruption has not been dealt with. There is still a sense of impunity. Daphne’s story is far from over.