Justin Gatlin's agent has slammed athletics chief Lord Coe's criticism of the American sprinter, labelling it "inhumane".
Coe said the 100m gold medal being won by the 35-year-old, twice banned for doping offences, was "not the perfect script" and added that he was "not eulogistic that someone who has served two bans has walked off with one of our glittering prizes".
Gatlin's victory, which denied legendary sprinter Usain Bolt gold in his final race, was greeted with booing by the crowd at the London Stadium on Saturday night.
"Lord Coe's a part of the IAAF who set the rules", Nehemiah told the BBC. "You don't allow them in and then still condemn them.
"I don't condone doping but Justin Gatlin is not the poster child for it. He's done his time, he plays by the rules, the IAAF reinstated him.
"They said if you come back we should accept that. So to put a narrative out that it's just Justin Gatlin and he's the bad guy, it's really not fair. It's inhumane. It's unsportsmanlike.
"He won the bronze medal here in 2012 and no-one said a word. No-one said a word in 2013, 2014 or even in 2015. It was only when he started to challenge Bolt it became an issue."
Nehemiah has previously criticised the BBC for its portrayal of client, taking issue with commentator Steve Cram's comments in 2015 that Bolt had "saved the sport" by beating Gatlin in that year's 100m World Championships final.
Gatlin's father, Willie Gatlin, said the booing of his son over the weekend was "disrespectful" to athletics.
"It doesn't upset me because I know what kind of son I raised, what kind of character he has," said Gatlin Sr.
"We didn't raise him to be like that. Speak with the tagalongs and the media and it is their loss that they can't enjoy these sensational moments.
"The fans booing is disrespectful to the sport. The sport has always been here and is going to be here after he leaves."