'My son could have been killed'

Lisa Thurgood said it was the second time this had happened to 17-year-old Darren in the space of a few weeks, and she was "sickened" to think he was being deliberately targeted.

Lisa, 41, of The Pallant, Maybridge, said: "It's absolutely awful. I have no idea why anyone would want to do this to him or who could be doing it.

"At first, we thought it might have been an accident so we didn't report it to the police, but when it happened a second time it was obvious it was deliberate. He could have been killed."

Darren set off on his Gilero Runner moped on Thursday morning to travel to Northbrook College, where he is studying carpentry and joinery.

But as he began to brake at the end of his road, nothing happened and had to use his feet to bring the bike to a stop.

He said: "It was pretty scary, but it was just lucky I was only doing about 10mph and there was no other traffic around at the time.

"I looked down and saw brake fluid leaking and without any you can't brake. I just had to put my feet down and hope for the best."

Darren, who is relying on lifts from his mum, had just saved enough money to pay for his motorcycle licence, but he will now have to use that, around 100, to pay for repairs.

Police confirmed they were investigating the matter.