Chocolate manufacturers said a steep rise in the price of cocoa and sugar was forcing them to consider increasing the price of their products.

Cadbury has increased the price of its Easter range by 5 per cent.

Spokesman Daniel Ellis said the price of cocoa had risen 150 per cent in three years and the price of sugar had gone up 120 per cent. ''[Raising prices] is our last resort,'' Mr Ellis said.

Cadbury restructured its three factories so that each now produces only one type of product. If you buy a block of chocolate, it is from Tasmania. If you're eating a chocolate bar, egg or Christmas tree, it's from Victoria. And if you are giving away a box of chocolates, they have come from Dunedin, New Zealand.

''Now, because costs of cocoa have skyrocketed, we are having to increase the wholesale price [of Easter products] … cocoa and sugar are now at the highest point we've seen in the history of Cadbury here,'' Mr Ellis said.

He cites this as a by-product of increased investment in raw commodities during the global financial crisis.

Max Brenner general manager Yael Kaminski Weiler said the company had not increased prices since 2007 but she did not rule out a future increase.

Lindt spokeswoman Sylvia Kalin said that in 2009, cocoa reached its highest price in 33 years and she expected the ''challenging'' prices to continue.

The cocoa price hike has also been blamed on weak crops and population growth in India and China.

Professor Helen Hughes, of the Centre for Independent Studies, said chocolate consumption in these countries has never been so high.