Eric Maleson, a former bobsledder who unsuccessfully stood against Nuzman for the Brazilian Olympic Committee (COB) Presidency in 2012, also made more allegations about the nature of Rio's lobbying in Africa.

He outlined to Judge Marcelo Bretas via video-conference how Ruy Cezar Miranda, a former advisor to ex-Rio de Janeiro Mayor Eduardo Paes, travelled with key bid officials to the continent shortly before the 2009 vote in Copenhagen at which the city was awarded the Games.

"Ruy Cezar had just returned from Nigeria with Carlos Arthur Nuzman," Maleson, founding President of the Brazilian Ice Sports Federation, told O Estado de S.Paulo in what he said was a summary of his testimony to Bretas.

"I knew him because of an attempt we had to bring an ice rink and it did not materialise. 

"But at that moment I questioned him about the trip to Nigeria and he replied making a gesture of money, implying that there was the purchase of support."

The Federal Public Prosecutor's Office in Brazil is in the process of investigating payments of at least $2 million (£1.5 million/€1.7 million) supposedly distributed to then-International Association of Athletics Federations President Lamine Diack from Brazilian businessman Arthur Cesar de Menezes Soares Filho in 2009.

The Brazilian city beat Madrid by 66 votes to 32 in the third round of a contest also featuring Tokyo and Chicago.

Diack was a voting International Olympic Committee (IOC) member at the time.

Brazilian newspaper Folha de S.Paolo also reported last week that testimony in a plea bargain agreement by Carlos Emanuel Miranda, a former partner of Cabral involved in the alleged scheme, claimed payments were made to four "African leaders connected to the athletics sector".

Nuzman was arrested last year in connection with the payments and was charged in October by the Federal Public Prosecutor's Office with corruption, tax evasion, money laundering and running a criminal organisation.

Nuzman and Cabral, sentenced to over 100 years for various separate corruption offences, each deny wrongdoing.

But Maleson has also alleged that there was a broader strategy between Cabral and Nuzman.

"The main objective was to ensure that these events brought visibility to Cabral and that they supported him in an application for the Presidency of the Republic," he told O Estado de S.Paulo. 

He reportedly alleges that Nuzman had struck an agreement with Cabral in which he would help bring mega-sporting events to Rio State as a means to enhance the latter's political platform.

It is not yet clear how much evidence Brazilian investigators have collected to prove testimony and allegations of bribes being paid.

The IOC claim to be assisting Brazilian authorities with their investigation.