The UK’s biggest security company has most recently worked with Abbott Mead Vickers BBDO, which was appointed to the business in 2006 after a three-way pitch.
AMV was responsible for creating an integrated DRTV campaign for ADT Security Services but claims that it no longer works with the company.
However, agency sources suggested that ADT Security Services has now approached agencies directly about the brief.
The media planning and buying account, which is held by John Ayling & Associates, is said to be unaffected by the review.
The company is one of the sponsors of The O2 venue and is billed as its "official electronic security supplier".
ADT Security Services claims to protect 89 of the UK’s biggest companies as well as more than five million homes and two million commercial properties worldwide.