The 30-year-old remains unimpressed with the forward after watching him in action for Brazil on Monday evening
The midfielder, who is currently on loan at Olympique de Marseille after he was deemed surplus to requirements by QPR at the start of the season, hit out at the forward last month and has again voiced his opinion that Neymar is overrated after watching the international friendly between Brazil and Russia.
"Neymar is the Justin Bieber of football. Brilliant on the old You Tube. Cat piss in reality...," Barton said on Twitter.
"Its amazing what some decent you tube footage can achieve. I'll have to get one up doing some keepy-ups in the garden...
"Neymar's actually been one of their livelier players tonight... But people should stop chatting pony. He isn't in the same stratosphere as the boy Messi and that Ronaldo fella...
"Stop going on about goals in Brazil Lge as well. I once scored 77 in 1 season in the Rainhill and Byrne u14 league and thats a stronger comp."
Neymar said last month that he had never heard of Barton after his first outburst, but has yet to react to the latter's latest tweets.