The trial of six Romanians charged with a dramatic theft from a Dutch museum is set to open in Bucharest Tuesday, amid fears the stolen masterpieces by Monet, Picasso and Gauguin may have been destroyed.
Five of the accused, including the alleged mastermind of the heist Radu Dogaru, are expected to be present at the hearing.
A sixth suspect is still on the run and will be tried in absentia.
Dogaru has admitted his guilt, according to his lawyers but investigators are still trying to determine what happened to the paintings.
Dogaru's mother Olga earlier this year told prosecutors she had torched the paintings in her stove in the sleepy village of Carcaliu in a bid to destroy evidence and protect her son.
Last month she retracted her statement.
But an analysis by experts from Romania's National History Museum revealed that ashes retrieved from her stove included the remains of three oil paintings and nails from frames used before the end of the 19th century.
The museum could not say whether these were from the paintings stolen in Rotterdam. However, four of the stolen artworks were oil paintings.
It took less than three minutes for the thieves to take seven masterpieces by some of the world's most famous artists from the Kunsthal museum in Rotterdam, one of the world's largest ports, in the pre-dawn heist on October 16, 2012.
Among the paintings stolen and carried away in burlap sacks were Picasso's "Tete d'Arlequin", Monet's "Waterloo Bridge" and "Femme Devant une Fenetre Ouverte, dite La Fiancee" by Paul Gauguin.
The total value of the haul, dubbed the "theft of the century" in the Netherlands, was 18 million euros ($24 million) according to prosecutors, while art experts at the time of the heist had claimed the paintings were worth up to 100 million euros.
"The theft was carried out according to a meticulous plan," prosecutors say in the indictment.
A Romanian art expert said Monday she gave the police crucial information which led to the arrest of three suspects, including Radu Dogaru.
In an interview with Romanian daily Adevarul and Dutch daily NRC Handelsblad, Mariana Dragu of Romania's National Art Museum said that in November 2012 she had been asked by a friend to appraise two paintings which he intended to buy.
After closely examining the two canvases -- "Femme Devant une Fenetre Ouverte, dite La Fiancee" by Paul Gauguin and "La Liseuse en Blanc et Jaune" by Henri Matisse -- she was shocked to discover that they were original.
Dragu said she did not immediately make the connection with the Kunsthal theft but when she did, she immediately called the prosecutor's office.
The Dutch police "could not believe" that the stolen paintings were in Romania, but Dragu had taken a picture which proved it, she said.
Two months later, three suspects were arrested in Romania, two of whom had been identified by Dutch police thanks to surveillance cameras.
The three suspects were Dogaru, 29, Eugen Darie and Mihai Alexandru Bitu.
Dogaru was already known to police, and is under investigation for murder and human trafficking.
If found guilty of "theft with exceptionally serious consequences", he incurs a maximum sentence of 20 years in prison.
Dogaru and his alleged accomplices all came from the same region in eastern Romania but lived in The Netherlands, and were under suspicion for robbery while their girlfriends allegedly were sex workers.
With little knowledge of art but eager to steal valuable old pieces, the group settled on the Kunsthal by chance.
After searching for museums on their GPS, the group initially found themselves at Rotterdam's Natural History Museum, but soon realised its exhibits could not be resold.
They then chanced upon a poster advertising an exhibition of 150 masterpieces from the private Triton Foundation at the Kunsthal.
Despite their value, none of the paintings was equipped with an alarm, Dutch authorities said.
The stolen paintings were transported to Romania by road, then hidden in Dogaru's village, Carcaliu.
The group tried to sell the paintings, but without success. A former model, Petre Condrat, accused of being an intermediary, is charged with concealment.
Olga Dogaru will also stand trial on Tuesday for aiding and abetting a theft. A separate investigation into the possible destruction of the artworks is pending.