JUST when you thought no-one was watching you... a new undercover investigator comes into town. In the age of Big Brother, catching out a cheating spouse or a dishonest employee is big business and one Wirral-based agent is pointing his long-reach lens at those doing things they really shouldn't in Ellesmere Port.

Thirty-five-year-old David Armstrong has been in the business of sticking his professional nose into other people's business since 1998 and has seen demand for his specialist skills grow dramatically.

He said: 'In this day and age of ruthless business competition and claims culture, we have to use every trick at our disposal to gather evidence.

'If a target remains static, walks, drives, uses a land line telephone, mobile phone or computer then, within reason, we can monitor them to gain evidence for our clients.'

David runs Executive Support Services with another operations manager and picks from more than 80 agents on his books when an assignment comes in.

David said: 'Most of them come from an ex-police, ex-special forces or ex-military background but we do have civilians too.

'Their most important quality has to be the ability to blend in. The more ordinary they look the better. They shouldn't look like what they are - a 6ft man mountain is no good to me.'

Advances in technology have led to a breakthrough in solving previously near-impossible cases and meant fewer places to hide.

All the agents have access to the very latest communications, surveillance photography, computer-monitoring and vehicle-tracking equipment.

The company has recently moved premises and aims to build upon the secret work it has already undertaken.

Cases have ranged from missing people, insurance claim frauds, industrial espionage and, of course, cheating spouses.

David said: 'We are very picky with what private jobs we accept and we always try to establish why someone wants someone followed. It can get very complicated between spouses.'

So how easy is it for a worried wife or suspicious husband to get someone watched day and night?

David said: 'Legally, as long as I am not peering through the window or on your private property I am not breaking any laws.'

But it's not all jilted lovers and big business - some cases even have happy endings.

David said: 'One of the most satisfying cases we had was to reunite two old friends who had lost contact with each other over 20 years ago.

'It took us about five minutes to find the person from our database and by the end of that same day they were on the phone catching up on old times.'

Executive Support Services' website is at www.geocities.com/execss