Nine claimed Holmes copped on-the-spot fines totalling $1412 for public nuisance and obstructing police for allegedly jumping a cab queue and becoming embroiled in an incident with a taxi driver early on Sunday morning.
It is believed the camp's 20-strong squad were told not to go out after returning from a team dinner on Saturday night.
However, up to six players still left for the Fortitude Valley nightclub precinct later that night.
New Queensland coach Kevin Walters had rammed home what had been expected from his Origin players just hours earlier at the camp - his first in charge of the Maroons.
"Our club has been made aware of an alleged incident involving Valentine Holmes amongst other players during a Queensland Emerging Origin training camp last weekend," a Cronulla statement said.
"We are conducting our own inquiries into this matter in addition to assisting the QRL with their investigation."
QRL managing director Robert Moore confirmed Holmes and Munster were the banned players.
"Cronulla Sharks player Valentine Holmes broke curfew during the Emerging Origin camp and is subject to further investigation by the QRL and NRL integrity unit," Moore said.
"Melbourne Storm player Cameron Munster has been excluded solely for breaking curfew."
Moore did not rule out bans against more players "if they were identified as breaking curfew".
Walters was furious.
"On Saturday afternoon, we sat down as a group and spoke about the importance of making the right choices," Walters said in a QRL statement.
"Regrettably, there were some players who made poor choices after we had wrapped up the official part of that day's program."
Walters had revealed to media when the camp started on Saturday that Broncos playmaker Milford had been earmarked for Origin duty this year.
Betros said it was the worst possible first impression Holmes and Munster could have made with Walters.
"The Queensland Rugby League won't be selecting them for anything for 12 months," Betros told AAP on Monday.
"It's a massive setback for those players. It's the only way they will learn.
"Kevin is very disappointed in them.
"He feels those players don't want to buy into what he is doing with Queensland.
"They can go back to club land."
Newcastle's Dane Gagai was also banned for 12 months for skipping a training session at the 2014 Emerging Origin camp.
He had to wait until game three last year to make his Origin debut for Queensland.
- AAP