Cocoa shipments from Nigeria's second-largest grower, Cross River State, have halted in the past week owing to a disagreement over a levy imposed by the state government on exporters who did not use the state's port to ship their beans, a trade body said.

Spokesman for the Cocoa Association of Nigeria, Godwin Ukwu, said yesterday that about 500 tonnes of cocoa due for export were held over the week after the local government refused to comply with a court order that it discontinue the duty.

According to Reuters, the Cross Rivers State government introduced a levy of N5,000 per tonne of cocoa on exporters who ship beans through ports other than the state's Calabar seaport, which diminished its viability. Taxes on exports including cocoa are usually collected by the federal government.

"The levy came into being in 2011 but we went to court to challenge it and we got a judgment restraining the government from collecting the money," Ukwu said, noting that shipments will resume once the levy is cancelled.

Officials from the state government were not immediately available to comment, Cocoa exports from Cross River are usually destined for Europe.

Abundant rain and sunshine in the two main cocoa areas of Ondo and Cross River States last month have helped the crop but there are fears that a lack of sun may allow diseases to spread hurt bean quality.

Ukwu said the logjam could affect output this season as farmers approach the main crop with export delays. Nigeria typically produces around 250,000 tonnes every year.

Cross Rivers is the second-largest grower with annual volumes of around 60,000 tonnes, in the world's fourth biggest cocoa producer.