European Union antitrust regulators have opened an investigation into the trade practices of Anheuser-Busch InBev (AB InBev) in Belgium, its home market.

The commission said it would probe if the company has “abused its dominant position in Belgium.” At issue is whether the brewer has used its market position to block cheaper imports of its beer from neighbouring countries entering the Belgian market, a breach of the commission’s rules.

Announcing the probe on Thursday, Ms Margrete Vestager, the commissioner for the agency, said that AB InBev’s strong market position in Belgium was “not a problem”, but added “we want to make sure that there are no anti-competitive obstacles to trade in beer within the European single market”.

She added: “Keeping out cheaper imports of its beer from neighbouring countries would be both against the interest of consumers and anti-competitive.”

The commission said that its initial view was that AB InBev “may be pursuing a deliberate strategy to restrict so-called ‘parallel trade’ of its beer from less expensive countries, such as Netherlands and France, to more expensive Belgian market.”

The regulator said it would examine whether the brewer had engaged in practices such as changing the packaging of beer cans or bottles in order to make it harder to sell them in other countries. It will also look into whether “non-Belgian” retailers have had their access to rebates and key products restricted so as to prevent them from importing less expensive beer products to Belgium.

If found guilty, the brewer could face fines of up to 10% of its global revenue, or be required to change its practices.

AB InBev said: “We are fully cooperating with the European Commission. It would not be appropriate for us to comment on the substance or potential consequences of the on-going investigation by the commission,” said an AB InBev spokesman.

Separately, a decision by the antitrust commission in January to overturn Belgium’s tax-discount plan for multinationals – including AB InBev – because it gives an unfair advantage to these companies and distorts competition, may have prompted the brewer to start shopping for a new home and may scale down its activities in Belgium once the merger with SABMiller is complete.