Consultancy firm Ernst and Young has warned that employees returning to work with new smartphones and tablets purchased over the Christmas period could be a security risk for companies.

The firm explained that companies with poorly protected networks, and those without policies on employee-owned devices were especially at risk, according to Computer Weekly.

In a statement reported by Computer Business Review, Massimo Cotrozzi, director of Ernst and Young's cybercrime investigations department said, "We are only in the first few days of 2015, but we are already seeing issues with companies leaving themselves exposed to this phenomenon."

"The new smart mobile/tablet and wearable tech that employees bring into the office could be now connecting via the corporate wireless networks to external cloud systems which, in the best case, have not been appropriately protected, let alone tested."

"Organizations that are unprepared could be caught napping while hackers are getting in, using employee devices, via the back door."

His advice comes on the back of the news that 75% of CIOs intend to spend more on security for their businesses in 2015 than they did in the previous year.

Computer Weekly adds that the issue is potentially compounded by cheaper tablets not always having the latest versions of software in place, out of the box.

While clear that prevention is undoubtedly better, Cotrozzi went on to argue that businesses should have contingency strategies in place: "Businesses also need to be prepared for when the worst occurs and have a clear strategy to respond to and clean up after an attack."

“Employees must understand how to preserve evidence left by the perpetrators and must also establish contingencies to deliver an instant response to reassure customers and prevent reputational damage.”