China’s Ministry of Commerce announced Wednesday it will extend its anti-dumping investigation into brandy imported from the European Union by an additional three months, Reuters reports.

The investigation, launched on January 5 and originally set to conclude after one year, will now continue until April 5, due to the “complexity” of the case, according to a brief statement from the ministry, which provided no further details.

The ministry had previously indicated the investigation could be extended by up to six months under special circumstances.

Preliminary findings released in October suggested EU brandy imports were being dumped into the Chinese market, threatening harm to China’s domestic industry. At that time, the ministry imposed provisional measures affecting major French brands, including Hennessy and Remy Martin.

The investigation is widely seen as retaliation for France’s support of EU tariffs targeting Chinese-made electric vehicles. French President Emmanuel Macron previously called the inquiry “pure retaliation.”

Beijing’s measures require Chinese importers to pay security deposits of nearly 40% to import brandy from the EU, significantly raising the cost of European brandy imports.

France’s Ministry of Commerce has previously called China’s actions “incomprehensible,” claiming they violate principles of free trade.

Last month, the European Commission formally filed a complaint with the World Trade Organization challenging China’s provisional anti-dumping measures.

Exports of French brandy to China reached $1.7 billion last year, accounting for 99% of the country’s brandy imports.