One August morning in 1990, Sergio Benedetti, who has died aged 75, walked the short distance from the National Gallery of Ireland, where he was a conservator, to 35 Leeson Street, a Jesuit community house. He was there by invitation to cast his eye over a number of paintings in the possession of the Jesuits, and was not expecting to find anything particularly startling.

In the event, his casual visit was a career-defining moment. On that fine morning Benedetti was, fortuitously, the right man in the right place. Extraordinarily, few people in the world were as well qualified as he to recognise, hanging in the Jesuits’ dining room, despite the dust and wear and tear of hundreds of years, a lost composition by one of the most celebrated painters in the history of western art: Michelangelo Merisi, known universally as Caravaggio.

Leaving the house, Benedetti could scarcely believe what he had seen, but he was confident that his instinct was correct. Prior to joining the National Gallery in 1977, he had become a specialist in 17th-century Italian painting, with a particular interest in Caravaggio and his followers. As a conservator, he was intimately acquainted with the very distinctive way Caravaggio worked, and he immediately suspected that he had seen the lost original of a painting known through many copies, and referred to by the artist’s contemporaries. The Taking of Christ, painted in 1602 for Caravaggio’s prominent patrons in Rome, the Mattei family, dramatises the moment of Christ’s betrayal and arrest in the Garden of Gethsemane.

Detective work

For Benedetti, there followed three years of intense analysis and historical detective work during which the painting’s history was pieced together. In the Mattei family archives, two Italian PhD students traced records documenting the commission of and payment for the painting. It had initially disappeared off the radar when it was mistakenly, and inexplicably, credited to Dutch artist Gerrit van Honthorst, while still in the Mattei collection. With the dispersal of many Roman art collections late in the 18th century, the Caravaggio made its way to Scotland, still labelled as a Honthorst. In that guise, it failed to sell at auction in 1921, was retained in the auctioneer’s stock, and was subsequently purchased by Dublin paediatrician Dr Marie Lea-Wilson (née Ryan).

As a young British army officer her husband, Percival Lea-Wilson, had directed the brutal ill treatment of Thomas Clarke following the surrender in 1916. But Lea-Wilson’s actions had been carefully noted by Michael Collins. When he was subsequently identified serving as an RIC district inspector in Co Wexford in 1920, he was immediately assassinated. His widow went on to study medicine and become a doctor. A devout Catholic, she presented The Taking of Christ to the Jesuits as a means of thanking them for the support they offered her in the years following her husband’s death.

Once its significance was appreciated, the Jesuit order entrusted The Taking of Christ to the National Gallery of Ireland on indefinite loan. In 1992, as his researches progressed, Benedetti curated an ambitious exhibition at the gallery, Caravaggio and his Followers, which included Caravaggio’s The Supper at Emmaus from the National Gallery in London. Then, in November 1993, The Taking of Christ was the centrepiece of the exhibition Caravaggio: the Master Revealed, also curated by Benedetti, which publicly announced its attribution to Caravaggio, and confirmed Benedetti’s role in one of the great art discoveries of the 20th century. The painting was also crucial to the more recent, and more extensive touring exhibition, Beyond Caravaggio.

From the start, the great scholar and collector Sir Denis Mahon, who was substantially responsible for the revival of interest in Caravaggio and his contemporaries in the 20th century, offered his services to the National Gallery of Ireland and was extremely helpful to the research process. Benedetti later curated the exhibition, A Scholar’s Eye: Paintings from the Sir Denis Mahon Collection at the gallery. In 2010, Mahon presented his library and archive to the gallery.

Following his appointment in 1977, Benedetti remained at the gallery for 30 years, as senior conservator and then as head curator. He worked on many important projects, including the conservation of Murillo’s The Meeting of Jacob and Rachel, and the return of Canova’s sculpture Amorino from the UK, and its restoration, with the support of Bank of Ireland.

Spiritual home

A keen researcher, he was professionally very focused and demanding, and expected high standards from those around him. Personally, he was extremely good-natured and something of a joker. Although he was born in Italian East Africa, his family soon left Africa and he grew up in Florence and came to love the city’s culture and cuisine. Indeed, those close to him knew that Florence remained, unwaveringly, his spiritual home throughout his life, including his years in Ireland.

When he retired from the gallery, he returned to Florence, where by all accounts he enjoyed life immensely, including pursuing research projects at the Uffizi library and regularly attending football matches, until his health declined in the last few years of his life. Caravaggio scholar and art historian Rossella Vodret, who brought The Taking of Christ to Rome for her 1995 exhibition Caravaggio and the Mattei Collection, said of Benedetti that he was both “a very serious scholar and an incredibly sunny person”.

Sergio Benedetti is survived by his wife Ita Collins, his son Gaddo and daughter Ginevra and his grandsons Nicoló and Hunter.