Prison population figures will not be published on Friday because of problems with a computer system, the Ministry of Justice has said.
The monthly Population in Custody bulletin, which includes a breakdown of the prison population by offence, sentence length and age, could be could be delayed for months, officials admitted.
It is the latest problem to arise out of the failure of the C-Nomis computer system, designed to track offenders "end to end", from sentence through prison to probation.
The project was scrapped after falling two years behind schedule and costing £690 million and was savaged in a recent National Audit Office report.
The Prison-Nomis computer system, which was salvaged from that wreckage, is behind the latest data problems.
A Ministry of Justice spokesman said "data collection issues" had emerged that needed to be fixed.
He said: "At present we believe that this suspension of the monthly bulletin is liable to affect publication of end of August data at the end of September and possibly future publications as well.
"A further announcement will be made when we can give a definite timetable for resumption of this series."
Figures for the number of prisoners released early to relieve overcrowding and prison population projections will be released as planned.
