The girlfriend of a young man who fell from a hotel balcony and froze to death overnight has paid a heartbreaking tribute to the love of her life.

And it is believed Rob Williams, 27, of Pigstye Green Lane, Willingale, near Chelmsford, may have fell after sleep walking at the De Vere Theobalds Park hotel in Waltham Cross, Hertfordshire.

He had been at the hotel with work colleagues following a Christmas party when he toppled about 13ft.

The building surveyor, and West Ham fan, was found suffering from severe hypothermia on a roof outside an unoccupied first-floor room the following afternoon after he didn't show up for work.

He was taken to the Princess Alexandra Hospital in Harlow, then transferred to Basildon Hospital.

He spent five days in intensive care, but died on Christmas Day without regaining consciousness.

His girlfriend of four years, Carla Hilton, wrote on Facebook: 'I am completely lost without you. When my phone beeps, I hope with all that I have that it is you.

'When a door opens, my heart races to see if it is you. With every minute that goes by, I think of you, talk about you, cry because I need you.'

A post-mortem examination revealed Mr Williams died from brain injuries caused as a complication of suffering from severe hypothermia.

It is not known if he was knocked out in the fall or simply stayed asleep.

His sister Kirsty Ashby, 30, of High Wycombe, Buckinghamshire, confirmed that Mr Williams had been a sleepwalker since he was young and his family believe he had been sleepwalking when he fell.

She said: 'We knew Rob sleepwalked but I don't think any of us knew how bad it was – it's only been from talking to his friends that we realised the extent of it.

'It had never caused him any problems before.

'My parents are struggling to take it all in. It has been an awful time for us all.'

Of her brother, she said: 'He was a really fun guy, someone you would always look forward to seeing.'

Police are treating the death as non-suspicious.