Despite being in the midst of a credit-crunch, the Fareham Heights-based firm extended an invitation to a camping weekend at Fairthorne Manor, Botley, to all 43 employees plus their families.

During the weekend, around 60 people turned out to enjoy activities including kayaking and abseiling during the day, and beer and barbecues in the evening, with a remaining 30 bedding down in tents to stay the night, before rejoining the fun on the Sunday.

The trip commemorates an extraordinary two decades for the small company, which has gone from building alarms from scratch in a garage, to multi-million pound government contracts to help slash crime in high-rise towerblocks.

Co-managed by sibling duo Alistair and Ian Austin, the company began as an attempt to beat existing alarm firms at their own game, by building their own.

Alistair Austin said: 'I had an alarm fitted in my home, and my brother realised that actually he could get the components for an intruder alarm much cheaper and build it himself.

'To be honest our first customers showed amazing faith in us. We were willing hobbyists, but had a great interest in it, and read everything we could get.

'At first we didn't know what the components were. We combed Exchange and Mart, contacted a few suppliers, and started experimenting.'

Alistair had been a car salesman in Southsea, and Ian was a London banker, and despite having no electrical training whatsoever, they began building the home-made devices in a garage in Waterlooville.

They discovered 'there was no black magic to it,' and by 1988 the Alarming Company was founded.

The company now has a turnover of around £2.2m, which it is in the process of doubling, with a deal with Southampton City Council.

The firm initially supplied burglar alarms to six tower blocks in Weston, Southampton, which have cut crime in the area by 80 per cent.

It is now working on a deal for 13 extra housing blocks in the city, which would make them the supplier of security systems to upwards of 6,000 people.