A French businesswoman known as the “paparazzi queen” is being questioned by police over alleged witness tampering in a case against the former president Nicolas Sarkozy. Michèle Marchand, known as Mimi, a powerful figure in the French celebrity press, was taken into custody with the Paris Match journalist François de Labarre, who was later released without charge. The investigation concerns an interview the magazine published with the French-Lebanese businessman Ziad Takieddine, one of the main witnesses against Sarkozy, who is accused of accepting millions from the former Libyan leader Muammar Gaddafi to fund his successful 2007 presidential campaign. While Marchand was being questioned, detectives searched her home. The investigative website Mediapart, which broke the story of Marchand and Labarre being taken into custody, said the inquiry centred on alleged “underground negotiations” with Takieddine for him to withdraw his allegations. On Friday, detectives were interviewing four more people, including Arnaud de la Villesbrunne, the former director at the Publicis agency, who was involved in Sarkozy’s unsuccessful 2012 re-election bid, on allegations of witness tampering and criminal conspiracy. Takieddine, 70, who was close to the Gaddafi regime, had alleged he delivered suitcases stuffed with cash from Tripoli to Sarkozy’s chief-of-staff in 2006-07. In Labarre’s “exclusive” Paris Match interview in November – which was accompanied by pictures taken by a photographer from the BestImage agency run by Marchand – Takieddine retracted his claims. Afterwards, Sarkozy, 66, went on television to express his anger at having been “dragged through the mud”, declaring: “The truth is out.” But when interviewed by investigators in Beirut in January, Takieddine claimed the magazine had misrepresented what he had said and reiterated his claims that Sarkozy had received money from Gaddafi. “Paris Match belongs to one of Sarkozy’s friends; they deformed my words,” he told them, according to AFP. Paris Match condemned the arrest of its journalist and said the police action was “contrary to all democratic principles”. Marchand, 74, is reportedly friends with Emmanuel Macron and his wife, Brigitte, and had previously organised press coverage for Sarkozy’s wife, the singer and supermodel Carla Bruni. Her lawyer has previously denied any wrongdoing on her behalf. During Macron’s 2017 presidential campaign, Marchand was credited with popularising the centrist candidate and his wife, persuading Brigitte to be photographed in a swimsuit in what were claimed to be “secretly taken” pictures. When Macron won, Marchand was pictured in the president’s office making a “v” sign. The Libyan case is just one of a series of investigations centred on Sarkozy. In March, he was found guilty of “corruption” and “influence peddling” and sentenced to three years in prison – two of them suspended – after instructing his lawyer to offer a senior magistrate a cushy job in exchange for information about a separate legal case into political donations. Sarkozy, who has repeatedly declared he has committed no wrongdoing, has appealed.