Javier Mascherano has spoken of the strain placed upon Lionel Messi by off-field allegations made against his Barcelona and Argentina team-mate.

Messi was this week linked to the 'Panama Papers', with his family quick to label claims of any wrongdoing as "false and libellous". The five-time Ballon d'Or winner is considering legal action against media outlets after being named in connection with documents from Panama-based law firm Mossack Fonseca.

> READ: Messi denies tax evasion in 'Panama Papers' scandal

The documents have been leaked to the international press and apparently include details of how the rich and powerful use tax havens to hide their wealth. Various media outlets have also alleged that the leak highlights evidence of illicit actions on behalf of some individuals, such as money laundering and tax evasion.

Messi and his father, Jorge, are currently facing a separate Spanish investigation into alleged tax fraud, relating to the football star's image rights, which goes to trial in Spain on May 31. Both father and son have denied those accusations.

Speaking after Barca's 2-1 Champions League win over Atletico Madrid on Tuesday, Mascherano - who reached an agreement with the Spanish authorities in January in relation to charges of tax fraud - addressed a question about the impact of the latest controversy involving Messi.

> READ: FIFA Officials, Messi, Platini named in secret offshore files

"Leo is very quiet, what can I say?" Mascherano said. "We all know and believe in the honesty of Leo. Unfortunately these things happen. I have been touched by times like this. There are friends, peers and family to support us in difficult times. But, simply, I say that Leo is really quiet."

The Panama Papers were passed to German newspaper Sueddeutsche Zeitung, which then shared them with the International Consortium of Investigative Journalists.

Not all the information apparently contained within the Panama Papers relates to illegal activity. Indeed, the use of offshore structures is entirely legal and there are many legitimate reasons for doing so.