Katrina Kaif has reportedly denied rumours that her sister Isabel has appeared in an online sex tape. According to In.com, the actress also said that the video which bears her sister’s name is a hoax and that the actress in the film is a lookalike. Reports suggest that Kaif is now planning to involve the authorities to protect her younger sibling. Isabel has reportedly been studying filmmaking in the US and has been spotted at various film events with her big sister. It has been alleged that she has already been offered some Bollywood roles but has turned them down because Kaif thinks that she is too young.