One source said the investigators have arrived in China, while another said visits are scheduled for this month and February.

The visits are for verification work - on-site inspections checking responses the automakers gave to questionnaires - one source said. European Commission documents for the probe say it is in the "initiation stage", with verification visits due by April 11.

The sources asked not to be named as details of the visit were confidential.

Last week, China opened an anti-dumping investigation on brandy imported from the European Union, a step that appeared targeted at France, which backs the EV probe. Popular Chinese models exported to Europe include SAIC's MG and Geely's Volvo.

Chinese-made vehicles' share of the European Union's EV market has risen to 8% and could reach 15% in 2025, with these EVs typically selling for 20% less than EU-made models.

In October, China's Great Wall Motor (601633.SS) said it was the first automaker to submit responses to the EU subsidy investigation.

Relations between China and the EU have been strained by factors including Beijing's closer ties with Moscow after Russia's invasion of Ukraine. The EU is seeking to reduce its reliance on the world's second-largest economy, particularly for materials and products needed for its green transition.

At the same time Chinese EV makers, from market-leader BYD to smaller rivals Xpeng (9868.HK) and Nio (9866.HK), are stepping up efforts to expand overseas as competition intensifies at home and domestic growth eases. Many have made sales to Europe a priority.

China is estimated to have overtaken Japan as the world's largest auto exporter last year, shipping 5.26 million vehicles valued at about $102 billion, a Chinese auto association said this week.