Statistics published by the Youth Justice Board show that as of December, there were 929 under-18s in custody, compared with 991 in November – a fall of 6.3 per cent.
The previous low was recorded in December 2014 when there were 956 under-18s in custody.
Numbers of children in custody have fallen dramatically in recent years. The figure hit a peak in June 2008, when it reached 3,072, but has dropped since then as a result of major attempts by various agencies to work to deal with more young offenders in the community.
However, although overall numbers are falling, disproportionality within the system remains on the rise. Of the 929 young people in custody, 41 per cent of them are young people who are black, Asian or from another ethnic minority background. In comparison, 57.6 per cent are white, with the backgrounds of the remaining 1.4 per cent unknown.
Last month, CYP Now reported that black, Asian and ethnic minority children are more likely to be sent to custody for knife possession than white children.
Publication of the latest youth custody figures comes in the same week it was announced that the government plans to turn young offender institutions (YOIs) into "secure academies" in an attempt to improve education standards in custody and reduce levels of reoffending.
The recommendation, which has received the backing of Prime Minister David Cameron, features in an interim report of a review of the youth justice system being conducted by Charlie Taylor.
Taylor has said he wants head teachers in the schools to be given autonomy and flexibility to commission services, such as mental health support and speech therapy, as well as recruiting and training their own staff.