This report claims that Fonua-Blake again crossed paths with Atkins in the tunnel on the way to the Manly dressing room, where he is said to have exclaimed "Are your eyes f***ing painted on you bunch of spastics."
The Daily Telegraph reported the NRL's match review committee was aware of the second tirade before handing down just a Grade 3 contrary conduct charge on Monday.
The NRL announced Fonua-Blake had been given a three-week suspension for the verbal abuse, which was reduced to two weeks after he entered an early guilty plea.
After the match, the Sea Eagles released a statement about the incident, revealing Fonua-Blake has personally apologised to Atkins for the outburst.
"Manly Warringah Sea Eagles prop Addin Fonua-Blake has tonight apologised unreservedly for his actions following the loss to the Newcastle Knights," the statement read.
"After returning to the dressing sheds, Fonua-Blake was very remorseful and sought permission to personally apologise to referee Grant Atkins which he then did."
The 24-year-old KIwis and Tongan international labelled his comments "regrettable" following the narrow 14-12 loss.
"Referees have a very tough job and we all need to respect their decisions, even when we may not agree with them,'' Fonua-Blake said in a statement.
"I should not have let my emotions get the better of me, and I am very sorry for the comments I made.
"I'd also like to offer my sincere apology to anyone offended by the regrettable language that I used.
"I let myself and my club down.
"That is not who I am or what this club stands for."
Although expletives are not uncommon on the footy field, the prop has come under fire for using ableist slang during his spiel.
Special Olympics Australia called out Fonua-Blake for using the "offensive" term on Twitter: "The R-word hurts because it is exclusive. It's offensive. It's derogatory. Language affects attitudes and attitudes affect actions. All clubs and players within @NRL need to be reminded of this."
On Monday, Brisbane Broncos premiership player Ben Ikin explained why he was unhappy with Manly's response to Fonua-Blake's outburst.
"The use of this word is so highly offensive to people living with disabilities," Ikin said on Fox League's NRL 360.
"The fact that this was not acknowledged - not by the player, not by the club, nor by the NRL - I think is an issue that needs to be addressed in the next couple of days."
Fonua-Blake has played 89 games for the Sea Eagles since making his NRL debut in 2016.
Manly are currently sitting in tenth spot on the NRL ladder and will take on the St George Illawarra Dragons on Sunday at Netstrata Jubilee Stadium.
