A father warned his teenage son about drinking too much at a wedding party before he was killed when he wandered in to the path of traffic on a motorway, it was revealed today.

Scott Turner was hit by a number of vehicles, including an unmarked police car, on the M23 near Crawley, West Sussex, in the early hours of Sunday morning.

The 15-year-old, from Burgess Hill, had earlier been having a "lovely day" at a family wedding at the Gatwick Europa Hotel.

His father, Andrew Turner, denied suggestions they had a big row, prompting his son to storm off, but said he may have felt "invincible" after drinking beer.

He told a local newspaper: "Scott had had a few beers, as 15-year-olds do, and I said to him, 'Scottie, I think you've had enough'.

"He said something like, 'No, I'm fine dad' and just walked away and went off to a car park with a few friends.

"There was no big row as everyone has been saying in the papers. He just got up and walked away with his mates.

"Obviously, if I was totally honest, he might have had more to drink than I thought.

"I really don't know much about the incident. I don't know what was going through his mind. But if you have had a few drinks you can feel very brave and invincible."

Paying tribute to his son, building contractor Mr Turner, 48, added: "He was a lot older than 15 in his attitude.

"He was a confident guy and he would be first in the queue to do something.

"To be honest, when he wanted to, he could be quite a handful, but his friends have said how polite he was.

"Obviously we are all devastated about this. It was a really happy day that turned into a nightmare for us all.

"I have spoken to my friends and they have said I only did what any parent would have done in speaking to Scott.

"I have got my head around that, but obviously I have got to live with the devastation for the rest of my life."

Scott's mother called police to report him missing at 1.46am. Three minutes later, police received calls from two separate motorists saying they had hit a pedestrian on the M23.

At 1.57am, medics in an ambulance - which had been to another accident and was taking people to hospital - reported that they also believed they had collided with a body.

Then an unmarked police car which was following the ambulance was also believed to have struck the pedestrian, the Independent Police Complaints Commission (IPCC) said this week.

The case was referred to the IPCC because of the involvement of the police car but the watchdog said it appeared Scott had already died before the police car became involved.

The motorway was closed for more than eight hours as officers investigated the incident between junctions 10 and 10a.

A post-mortem examination is not expected until later and no arrests were made.

Teachers at Downlands Community School in Hassocks, where Scott was a pupil, said he "had a ready smile which endeared him to staff and pupils alike".