RIO DE JANEIRO (Reuters) - Brazilian federal police on Thursday opened a new front in their investigation into alleged corruption involving Olympic projects, arresting Rio de Janeiro’s former head of infrastructure on suspicions he took bribes.

Police and federal prosecutors said in statements that 35.5 million reais ($11.4 million) in bribes were paid by companies that built a bus rapid transit system linking Rio’s main airport to Olympic areas, as well as works to clean sewage-infested waters near the Olympic village, which remain badly polluted.

Federal prosecutors said a consortium led by construction firms OAS SA and Carioca Engenharia paid bribes to officials at the federal Cities Ministry so they would free up funding to city officials for the projects. They also allegedly paid bribes to city officials once the firms were paid for their work.

Police arrested Alexandre Pinto, head of infrastructure in the government of former Mayor Eduadro Paes, who oversaw much of Rio’s Olympic efforts.

Brazil’s Supreme Court opened an investigation in April into Paes, accused in plea bargain testimony of taking at least 15 million reais in bribes related to Olympic contracts. He denies any wrongdoing.

Paes said in a statement on Thursday that it would be “a great disappointment” if the accusations against Pinto and about the overall scheme were found to be true. The former mayor underscored that Pinto was not a political appointee, but a career bureaucrat.

Pinto could not immediately be reached for comment. It was not clear who was providing legal counsel for him.

Thursday’s accusations were not the first to be made in connection with Brazil’s hosting of the world’s two largest sporting events - the 2014 World Cup and the 2016 Games.

In April, federal investigators alleged that contracts to build or refurbish at least six soccer stadiums, including Rio’s famed Maracana, were alleged to have been won by firms paying bribes to officials.

In March, investigators made arrests in connection to alleged bribes paid in connection to the extension of Rio’s subway line to the main Olympic area.

Investigators in France are probing whether money was doled out to members of the International Olympic Committee to vote in 2009 for Rio to win the right to host the Games.