Angolan billionaire Isabel dos Santos has called for her assets in Angola and Portugal to be unfrozen because she says there is evidence the state and courts colluded against her using fabricated evidence.

In January, prosecutors in Angola accused the daughter of the former Angolan president and her associates of mismanaging and embezzling $1bn (£800m) from the state oil firm.

Her assets in Angola and in Portugal were subsequently frozen.

Ms Dos Santos, who denies all the allegations, says one of the clearly fake documents used in court was a forged passport in her name which she says bears the signature of the late martial arts expert Bruce Lee.