A man was injured in a crash as he fled the wildfire at Winter Hill in van with an arson suspect last Thursday, say police.
The 22-year-old man from Bolton was travelling in the van with another 22-year-old man who was arrested on suspicion of arson with intent to endanger life.
The arson suspect has now been released under investigation.
Police say the injured man has since been released from hospital and has not been arrested.
Scores of fire crews continue to tackle the blaze which has been declared a major incident.
The origin and cause of the fire remain unknown.