By Paul Welsh BBC West Africa correspondent

New anti-smuggling measures have been promised in Ghana to stop illegal movements of cocoa into neighbouring Ivory Coast.

Cocoa prices are at a 15-year high, and because the government in Ghana buys all the cocoa produced locally at a lower fixed price, Ghanaian farmers have missed out on the boom.

By contrast, in the Ivory Coast, raw cocoa beans fetch the world market rate.

The smuggling caused by the huge disparity in the prices of cocoa between the world's two biggest cocoa producing countries is costing the economy of Ghana dearly.

Rising prices

Swinging his machete energetically, cocoa farmer Maxwell slashes away at the undergrowth which has sprung up between his trees.

You have some people from both countries who have turned themselves into professional smugglers

Kwame Sarpong, Cocobod

He is pleased he did not change crops when the price crashed.

"When the price was not very good some people were cutting down their cocoa trees," he says.

The increase in cocoa prices began late last year.

It has continued and it has led to cocoa smuggling because farmers in Ghana have the price for cocoa set by the government at the beginning of the season.

Over the border in Ivory Coast, the price rides with the market.

More prepared

Ghana's Cocoa Board (Cocobod) estimates that 50,000 tonnes of cocoa were smuggled over the border between December and February.

"You have some people from both countries who have turned themselves into professional smugglers," says Cocobod chief executive Kwame Sarpong.

Mr Sarpong said the smuggling slowed right down when the set price was raised in February but by then they had lost $50m worth of cocoa.

Ghana is the world's biggest cocoa producing country

"For an economy like Ghana it is very very significant," Mr Sarpong said. "We are going to move mountains to ensure that it doesn't happen again.

"In the past we have tried to stop this thing by putting the security agencies on the borders, it has helped but in the last year because it happened seriously abruptly we were really not prepared for it."

Insurance

At a warehouse in the Ivory Coast, sacks are filled with cocoa and sewn shut for export.

There is no way for the big international companies here to know whether some of the cocoa they are shipping is contraband.

But Ghana's government remains convinced that the fixed price system is best for its country because it raises money before the harvest on the futures market.

But on his small plantation Maxwell isn't convinced.

"I am not very happy. It must be changed. If it doesn't change, automatically there is temptation," he says.