Ostrich eggs are to appear in supermarkets across the UK in time for Easter, after sales rose by more than 500 per cent last year, a retailer said.

Waitrose will stock the egg - which is now in season - in 31 branches from next week after sales increased by 573 per cent between 2008 and 2009.

Each egg, costing £18.99, is equivalent to 24 hen eggs and can make an omelette large enough to feed 15 adults, according to the supermarket.

They have a mild flavour and need boiling for between 50 and 90 minutes, retaining their heat for up to two hours.

The eggs are laid by South African Black Ostriches on a farm in Lincolnshire. Eggs are laid four to five hours before dusk to protect them from the heat of the sun, replicating behaviour in the wild. Demand for pheasant, quail, duck and goose eggs had also increased, with sales of goose eggs increasing by 101 per cent, Waitrose said.

The retailer will sell ostrich eggs in an extra 11 stores this year and goose eggs in an additional 21 branches.

High profile restaurants including Scott's, Maze and Marcus Wareing at The Berkeley in London have all offered unusual eggs on their menus.

Waitrose egg buyer Frances Westerman said: "Britons have proved they are game enough to try something other than the humble hen egg. Customers have been seeking out something a bit different and the ostrich egg is a real trump card when it comes to cooking over the long weekend.

"What better way to surprise guests this Easter Sunday than boiling one egg for all your guests' breakfasts?"