It is a tragic story of love, power and loss, but Marina Litvinenko hopes an opera based on her husband’s murder will also help bring about something far more important to her: justice.

Alexander Litvinenko, a former Russian secret service officer, died after being poisoned with the radioactive isotope polonium-210 in London in 2006.

The story of his murder, by two assassins sent by the Kremlin, was the subject of a play at the Old Vic based on the book by the Guardian journalist Luke Harding. An operatic version based on Marina Litvinenko’s 2008 book, Death of a Dissident, will premiere later this year.

“For me it is about justice,” said Litvinenko, explaining why she was happy to see the story play out artistically.

She said despite a British public inquiry that showed compelling evidence against the people who murdered her husband, the two suspects were still living their lives in Russia with no prospect of extradition.

Litvinenko said that every time she helped bring the case back into the public consciousness she was doing so for the memory of her husband. “My motive is very personal. What I’m doing has never been politically motivated, it is all about love, a love story, the story of my husband,” she said.

She and her husband were living with their then 12 -year-old son in north London when he was murdered. There is overwhelming evidence suggesting the act was state-sponsored.

The idea of an opera about the case came when the composer Anthony Bolton listened to the audio-CD of the book written by Marina Litvinenko and Alex Goldfarb.

At the end, Bolton said he thought: “Gosh, this has to be an opera. It’s got all the ingredients – love, power, politics, betrayal, murder … everything.”

Bolton was working as a City fund manager at the time so shelved the idea until he retired in 2014. He bought the operatic rights and wrote the music over a three-year period to a libretto by Kit Hesketh-Harvey.

It was commissioned by Grange Park Opera, which in 2017 set up a theatre in the woods of West Horsley Place, a stately home in Surrey inherited by the former University Challenge presenter Bamber Gascoigne.

The opera will be performed twice in July, with seven soloists and a full chorus who at different times will be Russian soldiers, Chechen Muslims, football supporters and hotel bar occupants.

Bolton said he had incorporated into his opera Russian music such as a Red Army marching song, a Moscow football anthem, the Chechen national anthem, with flavours of Shostakovich, Rachmaninov and Tchaikovsky woven in.

The opera will be a very different show to A Very Expensive Poison, in which the playwright, Lucy Prebble, ramped up the absurd and comedic elements of the story.

Both the play and the opera have been commissioned by arts organisations which get little in the way of state subsidy.

Grange Park Opera’s founder, Wasfi Kani, suggested she was able to take quicker decisions because of her company’s size. “You can always think of a reason not to do something,” she said. “In these larger organisations every decision is made by multiples of people who the state is paying for and one of them will think of a reason not to do things, whereas all I have to do is talk to my trustees.”

Litvinenko said she had seen an orchestral run-through of the opera and that she cried at the end. Both she and her son, now 25, think they will get justice one day.

“If I was not optimistic I would not have been able to [do] everything I’ve done in the past 10 years,” she said.

• The Life & Death of Alexander Litvinenko is at Grange Park Opera, Surrey, on 16 and 18 July