Education Minister Joe McHugh has warned that building failures of the kind that caused the closure of a number of schools around the country and remedial works at others may warrant criminal investigation.

Five more schools built by Western Building Systems require remedial work, bringing the total number of schools with structural issues to 23, the Department of Education has confirmed.

The number of schools that require protective works prior to reopening after the midterm break has risen to 17, while question marks remain over a further 13.