Germany's Federal Cartel Office has launched an investigation into Amazon’s "double role" as the country’s largest retailer and biggest online host for small businesses, raising the pressure on UK regulators to take similar action.

Germany’s national competition regulator will look closely at factors that may be disadvantaging sellers, such as contract clauses restricting lawsuits against the tech giant and rules around the blocking and closing of sellers accounts.

“Amazon functions as a kind of gatekeeper for customers,” said Andreas Mundt, head of the Federal Cartel Office, also known as Bundeskartellamt.

“Its double role as the largest retailer and largest marketplace has the potential to hinder other sellers on its platform.”

The start of an investigation into Amazon’s operations in its biggest market outside the US is set to bring increased scrutiny to the retail giant across the European Union, with UK regulators and campaigners closely monitoring the situation.

The Competition and Markets Authority, Britain’s competition watchdog, said it was eyeing the situation in Germany and planned to consult with other national authorities.

The CMA said: “Promoting competition in digital markets is one of the CMA’s priorities. Technology has transformed some markets, and brought with it benefits such as increased choice and convenience, but it also gives rise to some risks to competition. We engage with other national authorities and will note the outcome of the German investigation.”