Nearly 100 weapons for Brad Pitt's new World War Z film were confiscated when they arrived in Hungary for filming.
The machine guns, rifles and pistols were sent from London to Budapest's Ferenc Liszt Airport.
Janos Hajdu, head of Hungary's Counter-terrorism Centre, said: "It's possible that all the weapons were brought in for the film, but this would not be allowed by Hungarian law," as the weapons had not been fully deactivated and could easily be used to fire live ammunition.
He said the weapons had been sent to a Hungarian company, whose representative was being questioned.
Mr Hajdu said that in Hungary weapons were considered to be deactivated only if the process "was irreversible," while the weapons seized could still be fired even though screws had been used to fill the end of the barrels.
Adam Goodman, whose company is providing production services for "World War Z," said he had been advised not to comment on links between the seized weapons and the film.
"We are preparing as planned. We are not changing our schedule," he said, adding that media reports claiming the film set had been raided by police to confiscate the weapons were "not true."
Hungary's National Investigation Office said it had launched a probe in the case.