Lyon: French police have arrested a cash van driver and his daughter, who claimed she was held to ransom while a gang robbed millions from her father's vehicle in Switzerland, police sources said on Tuesday. The father, daughter and a colleague of the father were taken into custody in Lyon on Monday, four days after they reported being the victims of a heist resembling the plot of a Hollywood movie. The 22-year-old daughter told police she was kidnapped from her apartment in the southeastern French city of Lyon by two men posing as plumbers. She said the men bundled her into a car, tied her up and forced her to telephone her father who works for SOS Surveillance, a Swiss company that transports cash in armoured vans, to demand a ransom. The father, who was en route with a colleague to the Swiss city of Lausanne with a cash delivery, then agreed to meet the kidnappers in a car park near the border with France and hand over the van's contents, the story went. French police last week estimated the loot at 20-30 million Swiss francs (17-26 million euros, 21-32 million). The daughter was found unharmed at around 10:00 pm on a road outside Lyon and appeared "very shocked" by her ordeal, police said at the time. Investigators now appear to suspect it was an inside job.