The latest discovery was made late on Wednesday night at 25 Midland Road, where Mr West, a 52-year-old builder, lived with his wife Rosemary, 40, in the early 1970s.
The body is widely believed to be that of Charmaine - Mr West's daughter by his first wife, Catherine - who vanished in 1970, aged about eight. Professor Bernard Knight, the Home Office pathologist, confirmed the remains as 'those of a young girl' after a brief examination at the scene. Last month, the remains of Charmaine's mother were found in a field near Kempley, 15 miles from Gloucester.
The latest find was exhumed from under the ground-floor kitchen at Midland Road, less than a mile from Mr West's home at 25 Cromwell Street, where nine bodies have been found. The remains were buried under more than six feet of reinforced concrete and steel, ballast and rubble.
Yesterday, Mrs West, who is in custody at Cheltenham police station, was charged with a fifth killing offence - that of jointly murdering 15-year-old Shirley Hubbard with her husband between 14 November 1974 and 27 February 1994. The girl, who was fostered at the age of six in Droitwich, disappeared on Friday 14 November 1974. A pupil at Droitwich High School, she had been doing work experience at Debenham's in Worcester when she vanished after leaving the store to travel home.
Mr West appeared at Gloucester magistrates' court yesterday morning charged with 10 counts of murder, including those of his first wife and his 16-year-old daughter Heather, his eldest child by Rosemary. Five of the charges had been amended to joint charges with Mrs West. They are for the murder of Linda Gough, Carole Cooper, Lucy Partington, Therese Siegenthaler and Shirley Hubbard. He was remanded in custody for a further 28 days.
Digging continued at Fingerpost Field, near Kempley, yesterday. The search at Midland Road was also due to resume after Professor Knight's visit to the site.
In a statement, Detective Superintendent John Bennett, leading the murder inquiry, said that 'positive lines of inquiry' were being followed in respect of the latest find.