By Lisandra Paraguassu
BRASILIA (Reuters) - Brazil's federal police and public prosecutors on Tuesday carried out an operation targeting senator Jose Serra and Jose Seripieri Junior, founder and former CEO of healthcare insurance firm Qualicorp, as part of a probe into illicit funding in the 2014 election campaign.
Sao Paulo state prosecutors said police have issued four preventive arrest warrants, including one for Seripieri Jr, who is accused of organizing non-registered donations to Serra's campaign when he was running for the Senate.
In a securities filing, Qualicorp confirmed police had searched its headquarters for documents linked to its former CEO, and that it was cooperating fully with the authorities.
Representatives for Serra said he has never received any unfair advantages during his 40 years of public life.
"It is important to emphasize that all his campaign accounts, managed by the party, were approved by the Electoral court," they said in a statement.
Qualicorp shares were down 5.7% in morning trading on the Sao Paulo stock exchange
Investigators have also carried out search and seizure warrants in other addresses linked to Serra in Brasilia and three other cities in Sao Paulo state, they said.
"In the course of investigations it was discovered that large payments made by large companies, one in the nutrition sector and another in the construction industry, were made to one of the companies allegedly used by the then candidate to conceal the donations," prosecutors said in a statement.
In a separate filing, Brazilian real estate group JHSF Participacoes SA (SA:JHSF3) said the company had also been targeted, with police searching for a potential contract signed with LRC Eventos e Promoções Ltda in 2014.
All individuals linked to the investigation have had their bank accounts frozen, according to prosecutors.