Metallica singer James Hetfield was investigated by UK airport officials who believed he was a terrorist this week, it has been claimed. The star was barred entry to Luton airport on Thursday and questioned by staff who were concerned about his appearance. Fears that Hetfield might be involved in terrorism were apparently founded on his "Taliban-like beard", according to The Times. He was allowed to leave the airport after a brief interrogation, when he persuaded officials that he was a rock star. Metallica play Live Earth at Wembley Stadium in London tomorrow, before headlining the venue for their own show on Sunday evening