Gunter Sachs: Playboy and husband of Brigitte Bardot who helped put Saint-Tropez and St Moritz on the jet-set map

When the German multi-millionaire playboy Gunter Sachs began romancing the French screen idol Brigitte Bardot in May 1966, he didn't do things by halves. After he arranged for a helicopter to drop hundreds of red roses over La Madrague, her Côte d'Azur property, the then most desirable woman in the world certainly paid attention. "It's not every day a man drops a ton of roses in your backyard," Bardot later wrote in Initiales BB, her autobiography. Her sex kitten role in And God Created Woman, directed in 1956 by her first husband Roger Vadim, had already put Saint-Tropez on the map but her relationship with Sachs, covered in great detail by paparazzi and reporters, transformed what had been a sleepy Mediterranean fishing harbour into a must-visit destination for the jet set.

Bardot and Sachs married in Las Vegas on 14 July 1966, a highly symbolic date – Bastille Day – for a union between two high-profile celebrities from former warring countries, sealed with a priceless "tricolore" wedding ring, yet neither party seemed fully committed to the relationship, and they divorced in October 1969. Bardot sold the ring but, in a grand gesture typical of someone with his moneyed background, Sachs managed toacquire it again and present it to his former wife, whom he remained fond of. The former actress was said tobe devastated on hearing the news that he had committed suicide at his home in Gstaad.

Born in 1932 in Mainberg, Germany, he was the scion of two rich industrial families, the car maker Opel on the side of his mother, Eleanor, and the manufacturers of motor parts Fichtel & Sachs on the side of his father, Willy Sachs. His father was a member of the Nazi Party and was arrested and investigated at the end of the Second World War but allowed to resume his business activities. Sachs was educated at the Lyceum Alpinium, the exclusive international boarding school in Zuoz, near St Moritz. He spoke several languages and studied mathematics and economics to prepare for a career as an industrialist.

In his twenties, he dated Soraya Esfandiary, who had been the second wife of the Shah of Iran, before marrying Anne-Marie Faure in 1956. The death of his first wife, due to an anaesthesia error during an operation following a car accident in 1958, and the suicide of his father the same year, acted as the catalyst for the continuation of a playboy lifestyle that made him a fixture of magazines like Paris-Match and Bunte throughout Europe. A handsome man with striking blue eyes, he escorted a succession of dazzling women including Britt Ekland and Aristotle Onassis's ex-wife Tina.

A friend of Vadim's, Sachs became a Saint-Tropez regular, renting a property from Bardot's parents before he even knew Brigitte, and then buying a seashore villa named La Capilla that was designed like a chess set. His parties on the French Riviera became as legendary as the ones held by the record mogul Eddie Barclay, who shared his fondness for white trousers. Sachs eventually met BB through her younger sister Mijanou – Marie-Jeanne – at Gassin, a picturesque village high above Saint-Tropez.

"I'd already known and loved many men, I'd had passionate affairs,"Bardot wrote in her autobiography. "But that evening, I was hypnotised.I seemed to be flying, as if carriedby Gunter into a fairytale world Ihad never known and would never know again."

Still, she turned down his first proposal of marriage but relented when he literally showered her with roses. After the Vegas ceremony, the couple honeymooned in Tahiti before heading back to Europe. However, they always led separate lives and famously didn't have a key to each other's Paris apartments. "While we were married, all told, I don't think we spent more than three months together," Bardot said. "I cheated on Gunter, of course, and he was unfaithful too, a lot more than I was."

In December 1967, Sachs challenged Bardot about the nature of her relationship with the songwriter and producer Serge Gainsbourg, issuing a "him or me" ultimatum that led to the shelving of the original version of "Je T'aime... Moi Non Plus" featuring BB and Gainsbourg, after just one airing on French radio station Europe 1. Revoiced by Jane Birkin, the heavy-breathing single topped charts across Europe in 1969, while the BB version was unreleased until the mid-1980s.

Following his divorce from Bardot, Sachs married the Swedish model Mirja Larsson and opened fashion boutiques in the fashionable resorts he frequented. He periodically returned to St Moritz and became chairman of its Bobsleigh Club in 1969 – Turn 13 of the St Moritz-Celerina Olympic Bob run is named in his honour.

A keen sportsman and a bon viveur, he also founded the infamous members-only Dracula Club, with its distinctive bat logo – his yacht in the Med was also called Dracula – in St Moritz. He did so much to reinvigorate interest in the Alpine resort that the local police turned a blind eye when he staged impromptu car races on the frozen lake in the middle of the night. He became a Swiss citizen in 1976 and spent much of his time at Le Vieux Chalet, his residence in Gstaad.

Sachs had always been interested in astrology, noting that he had overlooked the fact that Bardot and he had incompatible star signs when they married. In the mid-1990s he set up an Institute for the Empirical and Mathematical Examination of the Possible Truth of Astrology in Relation to Human Behaviour which studied data from the official statistics office in Switzerland. He published a book on the subject that became a bestseller in Germany and was translated into English as The Astrology File: Scientific Proof of the Link Between Star Signs and Human Behaviour (Orion Books). "In every case, there were significant results, way beyond what is explicable through mere coincidence," he said when promoting the book, whose profits he gave to his wife's charity for children.

A philanthropist, keen photographer and art collector, he built a considerable modern art collection, including works by his friends the Surrealist painter Salvador Dali and the Pop Art legend Andy Warhol, who portrayed him in his colourful trademark silk-screening style. Sachs enjoyed photographing female nudes and created surreal pictures, which he exhibited, and also made documentary films.

He also wrote a frank autobiography in which he reflected on the deaths of his first wife, of his brother in an avalanche, his father's Nazi connections, and his marriage to Bardot. "A year with Bardot was worth 10 with anyone else," he remarked.

Sachs was believed to have suffered from Alzheimer's. "The loss of mental control over my life was an undignified condition, which I decided to counter decisively," he stated in a farewell note released to the media by his family.

Fritz Gunter Sachs, photographer,author, philanthropist and industrialist: born Mainberg, Bavaria, Germany 14November 1932; married 1956 Anne-Marie Faure (died 1958; one son), 1966 Brigitte Bardot (divorced 1969), 1969 Mirja Larsson (two sons); died Gstaad, Switzerland 7 May 2011.