Matera had earlier on Tuesday issued an apology after the texts, reportedly related to comments about Bolivian and black people, resurfaced on social media.
The Argentine Rugby Union issued a statement saying it had decided to strip Matera of the captaincy.
“The Argentine Rugby Union strongly repudiates the discriminatory and xenophobic comments published by members of the Los Pumas team on social networks and meeting urgently, the Board of Directors resolves: In the first place, revoke the captaincy of Pablo Matera and request the staff to propose a new captain to the Board of Directors.”
The union has also suspended Matera, Guido Petti and Santiago Socino from the national team until they face disciplinary action. Petti and Socino are also accused of discriminatory texts.
”Although the messages were expressed between 2011 and 2013 and do not represent the integrity as people that the three showed during this time in Los Pumas, from the Argentine Rugby Union we condemn any expression of hatred and we consider it unacceptable that those who express them represent our country,” the union said in a statement.
The trio will face charges before the union’s disciplinary commission.
Earlier, Matera apologised. “I had a tougher time. I am very ashamed. Apologies to all those who were offended by the atrocities I wrote,” Matera said via Instagram.
“At that moment I did not imagine who I was going to become. Today I have to take charge of what I said 9 years ago.
“I'm also sorry to my team and my family for the moment they are going through my actions and thanks to the people who love me for their support.”
The 27-year-old flanker led the Pumas to an historic 25-15 victory over the All Blacks in Sydney last month, but they were soundly beaten 38-0 in Newcastle on Saturday night.
He has closed his Twitter account.
Matera issued another apology on Tuesday, after the Pumas came under fire for failing to pay tribute to Diego Maradona following the death of the legendary Argentine footballer.
The All Blacks earned international praise for paying homage to Maradona during their pre-match haka.
Matera’s allegedly discriminatory social media posts may have resurfaced as a result of the fallout.