Some cocoa exporters in top grower Ivory Coast are being forced to pay more than the government-set price for beans as tight supplies intensify competition and fears grow that a powerful El Niño could further curb output.

Exporters are paying as much as 20% above the official farmgate price of 1,200 CFA francs ($2.05) a kilogram for the main crop harvest, according to people familiar with the matter. The higher price is being demanded by middlemen who buy beans from farmers and sell them on to exporters, the people said, asking not to be identified because they’re not authorized to speak to the media.

Ivory Coast’s industry regulator, Le Conseil du Café-Cacao, prohibits exporters from paying above the official farmgate price. It has previously warned companies against offering more than the state-set price to secure deliveries. A spokeswoman for CCC couldn’t immediately comment when contacted by phone.

The competition for beans follows a sluggish start to the main crop, the larger of Ivory Coast’s two annual harvests, amid poor pod development. That’s raising concerns that some exporters may struggle to secure enough cocoa to meet their contracted volumes, potentially forcing contracts to be rolled forward, one exporter said.

While futures have been pressured by a large surplus from the previous season, rising domestic prices offer an early sign that the physical supply picture is tightening. On Tuesday, cocoa futures in New York swung between gains and losses, trading at around $5,400 a ton.

Supplies could tighten further, with El Niño expected to bring hotter and drier conditions to West Africa. More than half of Ivory Coast is already experiencing drought conditions, with the affected area forecast to expand, according to the Africa Flood and Drought Monitor.

Beans arrivals at the country’s ports are lagging behind last year, with deliveries since the international cocoa marketing season started Oct. 1 at 173,158 tons, down 43% from a year earlier.