The former head of Italian infrastructure group Atlantia, Giovanni Castellucci, has been put under house arrest by judges investigating the deadly 2018 collapse of a motorway bridge in Genoa, people with knowledge of the matter said on Wednesday. Castellucci, who also previously served as CEO of Atlantia’s motorway unit, Autostrade per l’Italia, was not immediately available for comment. Atlantia and Autostrade were also not immediately available for comment. The move, which sent Atlantia shares sharply lower, comes at a delicate moment for the group, which is in talks with a consortium led by Italy’s state-backed investor Cassa Depositi e Prestiti (CDP) over the sale of its 88% stake in Autostrade. Italy’s finance police said three former and three current managers at Autostrade had been targeted by the ongoing investigation but did not give any names. The development in one of the probes linked to the bridge disaster could increase the pressure on Atlantia to hand over Autostrade to the CDP-led consortium, cutting short tough negotiations over the valuation of the asset. At 1040 GMT shares in the infrastructure group were down 3.7% to 14.94 euros after trading was briefly halted following a 5%-drop. TRANSPORT SAFETY In a statement, the police said three people were under house arrest and three hits with “prohibitory measures” for allegedly failing to guarantee transport safety and for alleged fraud in public supplies. It said the managers were allegedly aware of defects in the safety barriers of the bridge, which was managed by Autostrade, and other potential hazards, but did not address the problems. The group and its managers have always denied any wrongdoing over the bridge collapse. The bridge collapsed in the port city of Genoa on Aug. 14, 2018, killing 43 people and triggering public outrage towards Atlantia and the Benetton family, which owns 30% of the infrastructure group. Since then Atlantia and Autostrade have been embroiled in a legal battle with the government over the future of Autostrade’s motorway concession. Last July the government orchestrated the sale of Atlantia’s controlling stake in Autostrade to CDP to re-gain control of the 3,000 km of roads managed by the motorway company.