SAO PAULO (Reuters) - Brazilian federal police carried out raids on Thursday in a probe of suspected corruption in the 2012 mayoral race in Sao Paulo, South America’s largest city.

Police said in a statement they were searching for evidence related to plea-bargain testimony given by the Ricardo Pessoa, the former chief executive officer of engineering firm UTC Engenharia SA.

Pessoa testified in 2015 that he was approached by the treasurer of the Workers Party (PT) to pay a 2.6 million-real ($806,501) debt that the campaign of the PT’s candidate, Fernando Haddad, had with a graphic design firm.

Haddad, who won the 2012 election but lost his re-election campaign last year, has denied any wrongdoing. UTC Engenharia did not immediately reply to requests for comment.

Pessoa’s plea-bargain testimony is part of Brazil’s larger “Car Wash” corruption probe that has seen over 90 people convicted, and led to a graft investigation into President Michel Temer, about a third of his cabinet and scores of sitting congressmen.

Separately on Thursday, federal police in Rio de Janeiro carried out raids and served one arrest warrant in a probe of suspected fraud in contracts to supply meals to schools and prisons.

The six-month-old investigation uncovered evidence that at least 12.5 million reais ($3.87 million) in bribes may have been paid to unnamed state government officials in Rio de Janeiro by a contractor, who was also not named in a police statement on the raids.