The witness who saw a naked man cut off his own genitalia with a large kitchen knife has told how he found it in a neighbour's garden.
The 23-year-old student, who did not wish to be named, said after calling the police he locked his own front door, afraid of what the man might do.
He said: "I looked out my bedroom window and spotted him standing on a wall waving a big knife about.
"He looked me in the eye, started screaming and then cut, it was obvious what he was cutting but I didn't stay to watch.
"I bolted downstairs and locked the door, told my flatmate, who grabbed something heavy – a push-up bar – as we didn't know what the man's intentions were.
"I was shocked. It seemed he climbed on the wall so someone would see him."
The incident happened on Friday night in Mutton Row, Penryn, where there are only a dozen or so houses.
Other neighbours are understood to have heard his screams and found him running around outside.
It is understood the man lives in the street with his wife and was inside his property when officers arrived.
A spokesman for the ambulance service said paramedics found him "bleeding heavily".
They took the 43-year-old to the Royal Cornwall Hospital at Truro for treatment where is in a stable condition.
Police were called at about 8.45pm.
A spokesman said: "We were concerned for the man's mental health."
The student went outside once the police arrived and said he spotted the appendage in a nearby garden and alerted officers.
"The whole thing is a bit strange," he added. "I didn't recognise the man at first, but when I realised it was a neighbour it was a bit unsettling."
