Thieve stole equipment worth half a million pounds from a security camera firm after

disabling its security system.

Staff at Owl Video Systems, Uckfield, arrived at work to find someone had cut through an inch-thick underground cable, disconnecting a network of alarms.

Stolen goods included plasma TVs, DVD players, and at least 50 video projectors worth £9,000 each.

The haul was so big two lorries were needed to transport it.

Dave Juby, owner of Owl Video Systems, said: "This was a professional job.

"We sell CCTV and video equipment, so we're quite advanced with our security systems."

The thieves struck between 8pm on Wednesday and 4.30am yesterday.

They gained access to the cable via a manhole cover in the road.

They smashed the alarm system attached to the wall of the building on the Bellbrook industrial estate.

They ripped out a metal framed window to gain access to the building.

Sixteen CCTV cameras were in place around the premises.

The thieves tilted the lower cameras, which were about 10ft above the ground, so they pointed at the sky instead of recording the robbery.

About eight higher cameras, which were 30ft above the ground, were left to record the robbery.

Mr Juby said: "It's a complete nightmare. They ripped our phones out, so God only knows how much business we've lost through that.

"Staff have spent hours on their mobile phones ringing round customers to let them know.

"And we've had to start begging manufacturers to help us fulfil our existing orders. It makes everyone demoralised. I started the company 20 years ago and I've never experienced a big break -in before."

A police spokesman said thieves drove off in a plain white lorry and a blue curtain sided lorry with a white cab.

A silver Peugeot 306 estate car with the registration YG51 GZF, was also stolen from outside the premises.

Mr Juby asked people to contact police if they were offered the stolen items, which included Fujitsu plasma TVs, Sanyo video projectors, and Mitsubishi projectors.