David BaleThe father of three Norwich-born children found dead in their home said the family is struggling to come to terms with the 'immense and tragic' lossDavid Bale

The father of three Norwich-born children found dead in their home said the family is struggling to come to terms with the 'immense and tragic' loss.

Eight-year-old twins Augustino and Gianluca Riggi and their five-year-old sister Cecilia were discovered on Wednesday at a townhouse in Edinburgh, after reports of an explosion.

Police are waiting to speak to the children's mother, US-born Theresa Riggi, 46, who is in a serious but stable condition in hospital after apparently falling from the second floor of the building.

It emerged today that the three children were born in Norwich and their parents lived for several years in Corton, just north of Lowestoft.

The children's father Pasquale Riggi has worked for Shell since 1987 and the family to the UK ten years later. He was based at Shell in Lowestoft from 1997 to 2002.

During this time the family are believed to have lived in Corton, where they were listed as being residents in 1998, but the children are believed not to have attended any of the local schools, as they were taught at home.

Many Shell employees formerly based in Lowestoft once lived in houses in The Woodlands and surrounding streets in Corton, although it is unknown whether the Riggis lived there, and neighbours could not remember the family yesterday.

The children's deaths are being treated as suspicious and post-mortem examinations were due to be carried out yesterday.

Mr Riggi, who was divorcing his wife, released a statement through Lothian and Borders Police, saying: 'Our family is struggling to come to terms with the immense and tragic loss of three beautiful children.

'Thanks to all who have offered such great comfort and support. We request that the media respect our privacy at this difficult time.''

Shell UK Ltd also issued a statement on the death of the children.

It said: 'This is obviously a human tragedy of proportions that most of us find hard to comprehend and our thoughts are with Pasquale and his family. Shell will continue to provide Pasquale with support .We would urge that he is left alone to deal with his great personal loss.'

Police had traced Mr Riggi to the Aberdeen area after the discovery in Edinburgh, where Mrs Riggi had been living since the beginning of July.

A judge warned that the children, who were at the centre of a bitter custody battle, could be in danger just 24 hours before they were found dead.

Judge Lady Clark raised concerns about the welfare of the children after their mother failed to appear at a divorce hearing on Tuesday.

The couple were due in court yesterday for a further hearing.

The family came from California and Colorado and Mr Riggi has been in Aberdeen for a number of years.

Edinburgh City Council said it was contacted by lawyers on Wednesday regarding the recent court proceedings.

It was around the same time that the authority was told about the incident at Slateford Road, Edinburgh.

Police hope the post-mortem examinations will determine how the children died and whether they should pursue a murder inquiry.

It was reported that the children were found stabbed to death in the flat before neighbours reported the explosion, but this has not been confirmed by police.

Sources in America revealed that Mrs Riggi grew up in a house in Baltimore, USA where her mother Patricia Butimore and brother Edward Butimore still live.

She married Pasquale Riggi at a church in Baltimore on September 30, 1989, and the marriage certificate listed her as a violinist.

Mr Riggi's parents are Mario Riggi and Silvia Saurini, who were both born in Italy.