SEOUL (REUTERS) - Japanese automakers saw their South Korean vehicle sales slump in July, data showed on Monday (Aug 5), as Japan's export curbs to Korea invited a consumer backlash.

Japan tightened controls in July on exports to South Korea, escalating a row over wartime forced labourers and sparking a boycott by South Korean consumers of Japanese products and services, from cars, beer and pens to tours.

Japanese automakers worry that the sales declines would continue this month, as Japan escalated tensions on Friday by removing South Korea's fast-track export status.

"Showroom visits are declining while consumers are holding off on signing contracts," a Honda Korea official told Reuters, asking not to be identified because of the sensitivity of the matter.

Toyota Motor saw its July sales in South Korea tumble 32 per cent from a year earlier to 865 vehicles, while Honda's sales skidded 34 per cent, according to data from the Korea Automobile Importers & Distributors Association (KAIDA).

Lexus, South Korea's third-biggest imported car brand after Mercedes and BMW, saw sales down 25 per cent to 982 from the previous month, although that was still up 33 per cent from the previous year.

A Toyota Korea spokeswoman declined to comment on the drop.