The heartbroken father of a six-week-old baby whose death sparked a major police investigation spoke of his pride in his "beautiful little girl".

Eighteen-year-old Robert McCall, who is separated from the baby's mother Ilona Matheson Sheach, 19, said last night: "My darling girl is in heaven and I pray that she will have a special place there."

He had seen baby Alexis Matheson only once before she was taken to hospital in Aberdeen in the early hours of Sunday morning, suffering from serious injuries. The baby was flown to hospital in Edinburgh for specialist treatment. Mr McCall travelled to Edinburgh in time to see his daughter christened Alexis Summer Matheson shortly before she died on Monday.

Alexis was born on October 26 weighing 6lb 15oz and her mother tells on her Bebo website how her happiest times were with her "wee tootie" and boyfriend Mark Simpson, with whom she had just moved in.

It is understood that for a time on Saturday night Mr Simpson was alone in their house in Deansloch Crescent, Aberdeen, with the baby.

A major investigation is continuing and an extensive forensic examination of the house has been carried out. Neighbours have also been questioned.

Mr McCall said: "I am totally devastated by what has happened. I am finding it very hard to come to terms with losing my wee girl just weeks after she came into the world. She was a lovely baby and I was so proud of her. I cannot believe she has been taken from us so suddenly and unexpectedly.

"In the years to come I was looking forward to seeing Alexis growing up and despite the fact her mother and I are no longer together, I would have hoped that I could have seen a lot of her and enjoyed a close relationship with her.

"Now all I have is a brief memory of my baby. The few photographs I have of Alexis, I will treasure always. It gives me great comfort to have been present at the hospital in Edinburgh when Alexis was christened with her close family present."

Detective Inspector Richie Guild, who is leading the inquiry, said the examination of the scene was completed on Wednesday night and house-to-house inquiries were nearly finished.

Police were waiting results of a post-mortem test, which has been completed.