Two people killed in an horrific fly-over crash at the weekend are thought to be brother and sister.

The 30-year-old man and 19-year-old woman died when a Fiat car smashed into barriers on the A19 fly-over between Middlesbrough and Stockton on Sunday morning.

Both were killed instantly in the high-speed crash but a third man, aged 19, had a miraculous escape, leaving the mangled wreckage with a broken leg and non-life threatening injuries.

The injured man, who is not related to the others, is still being detained at Middlesbrough General Hospital. Police officers investigating the smash, which some members of the emergency services described as the worst they have ever seen, have spoken to him and will interview him again at a later date.

Cleveland Police say the people involved in the accident were all returning from a 21st birthday party when the crash happened.

Officers can only confirm the dead siblings' identities when all relatives have been informed.

A force spokesman said they are still desperate to speak to anyone who may have seen the accident. He said: "We are renewing our appeal for any witnesses to the crash which happened at around 2.45am on Sunday.

"In particular we are keen to hear from people who may have been travelling across Newport Bridge, which runs parallel to the A19, and anyone who may have been walking home from Middlesbrough towards Stockton."

Anyone with information is asked to call Stockton police on (01642) 326326.