Indonesia's antitrust agency on Wednesday said last year's takeover of the country's biggest e-commerce platform Tokopedia by TikTok carried a risk of monopoly.

Hacker leaks 15 million records from Tokopedia, Indonesia's largest online store The Tokopedia data has been published on a well-known hacking forum.

TikTok will take a controlling 75.01 per cent stake in Tokopedia, an ecommerce unit of GoTo, the Jakarta-listed technology group told investors on Monday in a letter seen by the Financial Times.

Tokopedia, Indonesia's largest e-commerce platform, said it was investigating an attempted hack and claims that the details of millions of its users had been leaked online.