Further evidence over the controversial use of rooms which can be locked to hold pupils in Pembrokeshire schools has been passed to the police.

There have been at least five rooms in schools across Pembrokeshire in which pupils have been locked, startling new evidence has shown.

And assurances by Pembrokeshire County Council over the use of 'time-out' rooms have been labelled 'manifestly unreliable' by ministers.

Back in February, using the Freedom of Information Act, the Western Telegraph exclusively revealed further details about the controversial use of a padded, lockable 'time-out' room at the Neyland Pupil Referral Unit.

Concerns about the facility had first been revealed in a damning report by the Care and Social Services Inspectorate Wales and Estyn report in 2011.

In a statement at the time, the council told the Western Telegraph that no other school in the county had a similarly used facility but the Pembrokeshire Ministerial Board (PMB), has since found that Pembroke Dock School did have such a padded room.

The letter to council leader Jamie Adams from Education Minister Leighton Andrews and Deputy Minister for Children and Social Services Gwenda Thomas clearly states: "The PMB has discovered a very similar padded room at a primary school in Pembroke Dock. Furthermore this school had two other windowless rooms in which, according to records kept by the school in relation to the use of these rooms, children were routinely locked."

The letter said the new headteacher of the school had since discontinued the practice but "faced considerable opposition doing so."

It adds: "In the PMB's view, the existence and use of these rooms would have remained undisclosed but for the PMB's visit to the school."

It goes on to say: "We have since heard that there are, or have been, at least five rooms in which children were locked in the county and there may be several more. We understand that there is no evidence of records kept in relation to the use of these five rooms."

The PMB said that in late May it came to the board's attention that a further 18 rooms across the county were being used for 'time out' purposes and: "It would appear that the authority has only recently become aware of the existence of these further rooms as a result of the audit carried out as a direct consequence of the PMB's discovery of the additional rooms at Pembroke Dock School."

The letter says that the council's education service did not disclose the existence of the additional rooms to the PMB when they became known. The PMB was only informed by the council's head of children's services.

"It would appear that the head of children's services had not previously known of their existence, which is indicative of the PMB's view that the authority's education and social services departments work in 'silos' and there is disconnection between them at both strategic and operational level.

"The incident is also indicative of the authority's failure to inform and consult with the PMB appropriately."

The PMB said that, for the avoidance of doubt, 'time-out' rooms may be appropriate for children with certain behavioural problems but "it is not, however, appropriate for children to be locked in such a room, other than in the most exceptional circumstances for brief periods and under supervision."

The PMB said: "It is never appropriate for such rooms to be used or constructed for the purposes of detention or punishment.

"Use of such rooms must always be recorded. Since such practices may also constitute criminal offences, the evidence we have seen has been passed to the police."