Netflix's hit series Monster follows the depraved life and crimes of infamous American serial killer and cannibal Jeffrey Dahmer - but how much of it is accurate.

Glass, who spoke to Dahmer's family 'for years' before meeting the killer behind bars, said the series' portrayal of the murderer's childhood isn't entirely accurate.

While Monster depicts Dahmer's father Lionel as a concerned dad who believed his son was an alcoholic loser, Glass said this simply wasn't true. .

'The father never thought anything was wrong,' said Glass, adding that Lionel was an 'odd' man who perhaps wouldn't have noticed red flags in Jeffrey's behaviour.

While the details of Dahmer's sickening crimes between 1978 and 1991 and subsequent arrest are portrayed accurately, Ms Glass (pictured in 2014) says aspects of his formative years were completely fabricated.

In the series, Cleveland is portrayed as Dahmer's next-door neighbour in the Oxford apartments and has several troubling encounters with him. 

'That didn't happen,' Glass said of Cleveland's portrayal, adding: 'There was a neighbour who noticed a smell, but didn't complain.'

'That didn't happen,' Ms Glass said of Cleveland's portrayal, adding: 'There was a neighbour who noticed a smell, but didn't complain.' (Pictured: Evan Peters in Monster)

Glass also said the detail about Dahmer's father Lionel teaching him how to dissect animals as a child was unlikely to have happened

'I'm not sure that's true,' said Ms Glass, who developed a friendship with Dahmer's parents in the '90s

Ms Glass also said the detail about Dahmer's father Lionel teaching him how to dissect animals as a child was unlikely to have happened

Monster: The Jeffrey Dahmer Story has become Netflix’s ninth most-popular English-language TV series of all time in the span of just two weeks