BUDAPEST (AFP) - Hungarian authorities have been holding an active arrest warrant since 2016 for Sebastian Gorka, a former national security adviser to US President Donald Trump, according to local police and media.

The Hungarian news site 444.hu reported on Thursday that a reader had spotted the warrant on the local police wanted list.

Gorka, who holds Hungarian, US and British citizenships, spent eight months working as a national security adviser to Trump between January and August 2017.

Still visible on the police.hu website on Friday (Jan 19), the warrant dates from September 17, 2016, and states that Gorka is wanted for suspected "abuse of firearms or ammunition".

A police spokesperson told AFP in an email on Friday that he was unable to provide further details on the alleged crime that triggered the warrant.

News site 444.hu said it believed the warrant may refer to an incident in 2009, but Gorka dismissed the report on Twitter.

"I moved to America in 2008. (LEGALLY!)" Gorka tweeted.

"More FAKE NEWS!" he told the British daily Guardian online on Thursday.

Born in Britain to Hungarian parents, Gorka lived in Hungary for several years between the early 1990s and 2008.

A former editor at the right-wing news website Breitbart, Gorka gave several fiery television interviews in defence of Trump.

He now works as a security pundit for the US television channel Fox News.

While in the White House Gorka also met Hungarian Foreign Minister Peter Szijjarto in March last year.

The Hungarian foreign ministry told AFP on Friday that Szijjarto "was not aware of the arrest warrant".

"Preparing for a discussion with a high ranking White House official doesn't mean checking police.hu," it added.