BUDAPEST (Reuters) - Hungarian police have seized a stockpile of weapons that was shipped to the Hungarian capital for the production of a film about zombies starring Brad Pitt, a film crew member said on Tuesday.

Weapons expert Bela Gajdos, who has worked on the filming of zombie movie "World War Z" to ensure the safe handling of the weapons used, told national news agency MTI that each firearm had been converted to restrict its use to blank ammunition.

Gajdos added that the weapons were completely harmless and had already been used on a shoot in London.

World War Z, a big-budget horror film directed by Marc Forster and slated for release in 2012, recently shifted filming to Hungary from Britain.

"We had a police permit to bring these guns into the country," Gajdos told MTI, adding that the production had contracted arms experts to establish whether the guns complied with Hungarian laws.

But the guns were seized before experts could inspect them.

Adam Goodman, the producer of the film, was not immediately available for comment.

Janos Hajdu, the chief of the Hungarian Anti-Terrorism Center on Monday said the agency seized a large stockpile of weapons, which arrived from England on a chartered plane. He could not confirm whether the weapons were intended for the World War Z shoot.

The National Bureau for Investigation, which took over the case, said in an emailed reply to Reuters questions that it was conducting an investigation for abuse of arms and ammunition, but would not release any further details.

The weapons included hand guns, machine guns, high-precision sniper rifles, hand grenades and a large quantity of high-caliber ammunition, according to photos and a video released by the Anti-Terrorism center.

According to the video, some weapons could be re-converted to use live ammunition by removing a single screw.

Hajdu said the firearms had not been properly disabled and could not be allowed into the country less than two weeks before a national holiday commemorating the 1956 uprising, MTI reported.

(Reporting by Marton Dunai, editing by Paul Casciato)