Lionel Messi announced a press boycott on Tuesday after a journalist alleged Messi's Argentina teammate Ezequiel Lavezzi used marijuana at the team's training base.

Standing in front of the entire national team at a post-match media conference following a 3-0 win over Colombia, Messi said the players would no longer speak to the press.

"We have made the decision not to talk to the press anymore, obviously you know why," the Argentina captain said.

"There were a lot of accusations, a lot of disrespect, and the accusations they made against Pocho (Lavezzi) are very serious," the Barcelona superstar said.

In explaining the boycott, Messi, who scored a stunning free kick goal and set up two others in Argentina's win, said the team was happy to take genuine criticism of its performances.

"We know that most of you guys don't play that game of disrespect. We can be criticized if we lose, or win, or if we play well or badly. But this is getting into personal lives," Messi said.

"If we don't put a stop to it now, we'll never stop it."

Lavezzi, who plays for Chinese side Hebei Fortune, was accused by an Argentine radio journalist on Twitter of smoking marijuana at the team's training camp.

Lavezzi has denied the claim and vowed to take legal action against the journalist for "false statements against me and the serious damage generated to my family and my work."

The 31-year-old did not play in last Thursday's 3-0 loss to Brazil and was left off the substitutes bench for Tuesday's match.

Brazil still perfect

Meanwhile, Brazil made it six wins in as many games as goals from Gabriel Jesus and Renato Augusto handed it a 2-0 triumph over Peru on Tuesday.

And in Santiago, Alexis Sanchez scored twice after returning from injury to give Chile a 3-1 win over Uruguay.

Manchester City-bound teenager Gabriel fired Brazil into the lead in the 57th minute, then set up China-based midfielder Augusto in the 78th.

The victory leaves Brazil four points clear at the top of South America's World Cup qualification standings with 27 points from 12 games.

With six games still remaining, Brazil is all but certain of securing one of the four automatic spots for the 2018 finals in Russia.

Uruguay is second with 23, while Chile is now fourth, with 20 points.

Argentina sits in fifth position with 19 points.