nd colleges will need to carry out new checks on existing staff. These are when: • an individual working at the school or college moves from a post that was not regulated activity with children into work which is considered to be regulated 91 activity with children. In such circumstances, the relevant checks for that regulated activity must124 be carried out • there has been a break in service of 12 weeks or more, or • there are concerns about an individual’s suitability to work with children. 349. For colleges, an individual moving from a position that did not involve the provision of education to one that does, must be treated as if that individual were a new member of staff and all required pre-appointment checks must125 be carried out (see paragraph 235). Duty to refer to the Disclosure and Barring Service 350. When an allegation is made (see Part four), an investigation should be carried out to gather enough evidence to establish if it has foundation, and employers should ensure they have sufficient information to meet the referral duty criteria explained in the DBS referral guidance, which can be found on GOV.UK. 351. There is a legal requirement for schools and colleges 126 to make a referral to the DBS where they remove an individual from regulated activity (or would have removed an individual had they not left), and they believe the individual has: • engaged in relevant conduct in relation to children and/or adults, and/or • satisfied the harm test in relation to children and/or vulnerable adults, and/or • been cautioned or convicted of a relevant (automatic barring either with or without the right to make representations) offence. 352. The DBS will consider whether to bar the person. Detailed guidance on when to refer to the DBS (including what is the harm tes