Brazil's federal police on Friday conducted raids at JBS SA to investigate the alleged use of insider information in financial market dealings between April and May, the authorities said in a statement.

Shares in JBS SA, the world's largest meatpacker, reached a two-week intraday low on confirmation that police raided the company and its majority shareholder, FB Participações SA, in connection with an insider trade probe.

"There is evidence these dealings occurred with the use of privileged information, generating undue advantages in capital markets in a context in which almost all investors incurred financial losses," the police said in their emailed statement.

JBS had no immediate comment on the raids.

JBS stock fell 4.95 percent to 7.11 reais in mid-morning trading while the benchmark Bovespa index fell 0.41 percent to 62,425 points.

The federal police served three search warrants at the offices of JBS and FB in Sao Paulo, and also detained four unnamed people for questioning.

The probe centers around two events, the police said, referring to the sale of shares in JBS by FB Participações at the end of April, and trades in currency futures and derivatives markets between the end of April and May.