This morning an Australian investment banker pled guilty to chaining a fake bomb to a young woman's neck in an extortion attempt last year.  

His lawyer entered the plea while he appeared in court by video.

The 18-year-old girl was alone studying at her family's home in August when the 50-year-old tethered a bomb-like device around her neck while wearing a ski mask and wielding a baseball bat. 

It took a bomb squad 10 hours to remove the device, however it contained no explosives.

The man faces a potential maximum sentence of 20 years in prision.