The luxury hotel whose occupants included Nazis officials and concentration camp survivors

The Left Bank of the River Seine in Paris conjures up great art, passionate love affairs and mouth-watering food. But taking pride of place in the 6th arrondissement is a hotel with a secret wartime past that is as shocking as it is fascinating.

The Lutetia opened in the early 1900s and was soon noted for its magnificent architecture and its celebrity guests. It was the favourite of many famous names, from Pablo Picasso to jazz singer Josephine Baker and novelist André Gide. It was Irish writer James Joyce's final address before he died, while Charles de Gaulle spent his wedding night there. It was also a hotbed of anti-Nazi resistance in the 1930s, with Heinrich Mann and Willy Brandt becoming known as "the Lutetia Crowd" by the Nazi high command for plotting the downfall of the Third Reich in its luxury salons and bars.

In its comings and goings, there is something slightly reminiscent of Wes Anderson's Grand Budapest Hotel film and it forms the backdrop to my new novel A Murder in Paris.

Following the German invasion, the Lutetia filled with exiles fleeing the Nazis, especially displaced musicians, artists and writers, thanks to its bohemian reputation.

But after the French government evacuated Paris in June 1940, the Germans entered the city. Some residents of the Lutetia escaped, others were taken into custody and the Lutetia itself was occupied by the Abwehr, the German counter-intelligence agency, with its luxurious rooms used to house high-ranking Nazi officers.

But the rebellious history of the Lutetia proved oddly prophetic. One of the officers was Admiral Canaris, who was part of an attempted coup against Hitler - a plot which later inspired the Hollywood blockbuster Valkyrie starring Tom Cruise.

What would become perhaps the Lutetia's most fascinating chapter, however, was still to come. Once Paris was liberated in August 1944, and Charles de Gaulle returned to lead a new government, the Lutetia was used by Allied troops, before being taken over by the state to accommodate French citizens returning from the concentration camps.

Survivors of the camps would arrive at the Gare D'Orsay and then be taken to the Lutetia. They underwent medical checks and were interviewed by the police during stays of a few days, before leaving to restart their lives. It's a truly incredible thought. Imagine staggering out of the concentration camps and then returning to the streets of Paris and staying in the Left Bank's most luxurious hotel.

People who had experienced unimaginable traumas were suddenly walking through these hallways filled with memories of pre-war Paris and the jazz age.

There are amazing photos of survivors sitting in the dining room of the Lutetia still in their striped clothes from the camps.

Their faces are caked with dirt and dust. Seeing them against the backdrop of such pre-war luxury brings home the reality of what happened and how the ordinary and the extraordinary lived side by side.

But the Lutetia was also a place of danger. Scores were being settled and no one was truly safe. After the liberation, people started getting revenge on those who collaborated with the Nazis. In order to escape punishment, some collaborators disguised themselves as camp survivors and entered the Lutetia in order to reinvent their own pasts and assume new identities. The police interviews were designed to catch collaborators pretending to be survivors.

Reading about what happened inside the walls of the Lutetia and learning about its history was the inspiration for A Murder in Paris. It also meant a research trip to the city.

But visiting the hotel during my visit was one of the most haunting experiences of my life. As The Eagles sang of their own Hotel California, "You can check out any time you like, but you can never leave": the memories remain.

The hotel, now a Mandarin Oriental, has undergone many revamps and renovations in the last 80 years, but there are still so many echoes of the past in the hallways and on the streets. The Lutetia might look glossy and luxurious, but it's impossible to forget what once happened here, and the secrets and memories hidden inside its walls.

As I walked through the hotel and wandered the nearby streets making notes and soaking up the atmosphere, I reflected on the idea of memory and, specifically, the idea of false memory.

I knew it would be a cornerstone of A Murder in Paris. I was fascinated by how we edit our memories every time we access them. Experts say we all have false memories that we have edited hundreds of times.

Whether it's how hard you worked at school, the time you met your future husband or wife, your successes or failures as a parent - we remember things the way we wished they happened rather than how they actually did. A Murder in Paris starts with a memory expert in London getting a call to say that her elderly grandmother has walked into the lobby of the Lutetia Hotel, claiming she once committed a murder in Room 11 and was known under a different name.

When the grandmother is later found dead, it appears her confession has unlocked a terrible secret from the past. The memory expert is plunged into a race-against-time quest to discover why this secret is so dangerous and soon finds her own life is in danger.

In truth, our memories are not like photos. They don't stay the same over time. We remember what we want to remember and often forget the rest.

There is even a technical term for this in relation to Paris and the Second World War. It's called résistancialisme. This is the idea that everyone claimed after the war to have been active in the Resistance when, in reality, very few were. The myth of the Resistance became a kind of collective false memory, one that was actively encouraged by De Gaulle himself, who rallied the nation by claiming that all true French citizens resisted the Nazis - quietly forgetting about Vichy.

During my research, contemporary debates about memory gained relevance in relation to one of the key hot-button issues of our time, the culture war.

We saw it in the protests over statues, or who is and isn't included in the history books and whether figures from the past like Churchill need to be celebrated or re-evaluated in light of our modern concerns.

What we remember, and how we remember, is now central to many of the most heated arguments. And it is incredibly important when it comes to recalling the 20th century's greatest and most destructive conflict.

For, 80 years after VE Day, the last living survivors of the Second World War will soon no longer be with us. The greatest generation will become part of history.

It's hard to believe that the Second World War will soon only exist in books, films, paintings, statues and buildings. But, as I walked through the Lutetia, I realised history has a way of clinging on.

It's not just the plaque outside which acts as a memorial to what happened at the Lutetia. It's the fact that it happened on the very ground you walk on.

The hotel is alive with the memories of what happened here. The human witnesses to what happened might soon depart, but these buildings live on.

So think of that as you apply the last of the sun cream, queue for the gelato or sip a café au lait this summer during your break. And if you find yourself in Paris near Boulevard Raspail, take a walk to number 45. You won't regret it.

The fact is, the places all around us are full of memories that make up the past, but also define our present - both true and false.

As Marcel Proust once wrote: "Remembrance of things past is not necessarily the remembrance of things as they were."

That also means you won't remember the delayed flight, the terrible airline sandwich or the family squabble on the fourth day.

Which is probably just as well. After all, false memories can sometimes be useful too.

• A Murder in Paris By Matthew Blake (HarperCollins, £16.99) is out now and available from all good bookshops