Nigel Stepney, the former Ferrari engineer at the centre of the Formula One 'industrial espionage' furore, has fled Italy and is in hiding with his girlfriend and their one-year-old daughter. He feared for his safety after harassment, involving high-speed car chases and the placing of a tracking device on his car, made his life unbearable.

Stepney, 47, speaking for the first time since being sacked by Ferrari for allegedly passing confidential documents to McLaren's chief designer, Mike Coughlan, told The Observer last night: 'There have been high-speed car chases. We've been followed by more than one car, with Italian plates, and when we cornered one of them last Thursday evening the men in it refused to speak. I don't believe they were journalists. Ash [Stepney's girlfriend] has been stalked at the house. There was tracking gear on my car. Someone was going to get hurt. I had no option but to get out of Italy.'

It emerged last week that McLaren had suspended Coughlan after documents belonging to Ferrari were found at his home. Stepney, already under investigation by Ferrari, and the Carabinieri, after allegations of attempted sabotage of the Italian team's cars before the Monaco Grand Prix, was assumed to be the source of the documents but is protesting his innocence.

'I categorically deny that I copied them [the documents], or that I sent them to Mike Coughlan. I knew I was being watched all the time at the factory and that everything I did or said was being reported back and that people knew whenever I accessed files on the computer. I have no idea how anything came into Mike's possession. If he has some documents, they came from another source.'

'Ferrari took that badly. I began to feel like I was some sort of traitor. As soon as I went against the system at Ferrari, I got squeezed. I'm anxious, naturally, but I haven't done anything wrong.'