The world's first 'iGrave' that uses GPS satellite tracking technology to help people to find their loved ones has been unveiled in the US.

Everyone buried at 'The Preserve' -- a 1.5-acre natural burial site in Lafayette -- receives a GPS transmitter disk in the center of their casket, or in the grave if there is no casket.

The battery powered devices, based on systems usually used to locate buried water pipes or gas mains, last for several years, and are roughly the size of a hockey puck.

The high tech burials are designed to allow staff and family members to find their loved ones exact location in a burial ground where graves are not marked.

Staff and family will be given special readers to direct them to the correct area, said Joe Canaday of Hippensteel Funeral Service and Crematory.

"It's like reading a bar code," Canaday was quoted as saying by the Daily Mail.

People who are cremated also receive a GPS transmitter, Canaday said.

The GPS locator can read up to five feet deep, and staff expect to have to use it when the graves become covered with grass and plants in the natural burial ground.

Natural burial grounds around the world have previously given mourners the GPS co-ordinates of their loved ones. But, The Preserve is believed to be the first to actually place a tracking device in each casket.

Natural burial grounds, where bodies are placed in open woodlands, have become increasingly popular in recent years.

Bodies can either be buried, or ashes sprinkled or even buried under trees of plants. Biodegradable coffins are used, allowing the body to decompose more quickly, with cardboard, wicker or other materials often used.