An island off the north-east coast of Tasmania could become the home of an eco-tourism venture, according to the real-estate agent who sold it.

Key points: Singaporean businessman bought Waterhouse Island for close to $5.5m

Singaporean businessman bought Waterhouse Island for close to $5.5m Group of families owned island prior for holiday spot

Group of families owned island prior for holiday spot New owner has future plans for eco-tourism development on island

It is understood a Singaporean businessman bought Waterhouse Island for close to $5.5 million.

The almost 300-hectare island has a homestead, cottage and shearing shed from its days as a sheep-grazing property.

Real estate agent Ant Manton said the island's permanent power supply, mobile phone reception and airstrip were among its many advantages.

"There are other islands obviously around the place, but a lot of them aren't freehold and certainly don't have the ability to land a plane on them, are as arable as this one is and obviously have the established facilities," he said.

"But it's just a magnificent isolated untouched island."

A group of families had owned the island for the past 45 years and used it as a holiday spot.

It sits 30 kilometres from Bridport and has a wharf and lighthouse.

When first put on the market last year it received interest from across the world.

"We were staggered," Mr Manton said.

The new owner's initial plans are to use it as a getaway.

"I think down the track there might be some plans for an eco-tourism type development, but at this stage just a magnificent private retreat in the middle of Bass Strait," Mr Manton said.

"But obviously there would need to be significant upgrades to services if they were going to use it any further."