Brazil coach Dunga said he was contemplating suing his 1994 World Cup-winning teammate Romario over the suggestion that his team selection was influenced by commercial partners.

In an interview with Italian newspaper La Gazzetta dello Sport, Romario, now a senator in Brazil and a campaigner against corruption, questioned whether Dunga was “involved in the Brazilian football confederation’s dirty ways.”

“I don’t know if he is dirty, if he participates, but he is seeing everything,” Romario said. “He is not blind or stupid.”

The former Barcelona striker accused the Brazil Football Confederation (CBF) of allowing football agents to influence selection. Brazil’s technical director, Gilmar Rinaldi, was a player agent before becoming Dunga’s assistant in July last year.

However, Dunga denied he had been influenced and threatened to take legal action against his former team-mate.

“Like all Brazilians, senator Romario has the right to criticize the choice of players selected to represent Brazil,” Dunga said in a statement.

“But he doesn’t have the right to say, without proof, that selection is based on non-technical criteria. I repudiate declarations from somebody who calls himself a friend, but isn’t. Friendship requires respect, loyalty and utmost confidence in integrity. For that reason Romario has never been my friend and he is obligated to present the facts,” Dunga said.

Dunga added that he and Rinaldi were “looking at the legal measures available with respect to the senator’s declarations”.

Romario has been an outspoken critic of the CBF and in May instigated a congressional investigation into allegations of corruption within the organization.

The 1994 World Cup winner spoke earlier this week of Michel Platini’s bid to succeed Sepp Blatter as Fifa president. Romario suggested that as a Fifa insider the Uefa chief was no better equipped at  dealing with corruption than the outgoing president.

“Blatter’s at the head of this school of dishonest people who can influence the world of football without necessarily being corrupt,” Romario stated.

“I can’t say that Platini is corrupt. But it is clear that his way of leading UEFA is not the best. Platini is part of this world and there is nothing positive in his management.”