Brazilian police arrested at least 40 people on Tuesday, including senior executives at Cisco Systems Inc, in a massive tax fraud investigation targeting the U.S.-based technology and network company, authorities said.

Police and tax authorities said Cisco's Brazilian unit had imported $500 million worth of tele-communications and network equipment over the last five years without properly paying import duties.

In all, the company owes an estimated 1.5 billion reals ($826.4 million) in taxes, fines and interest, police said.

Five more suspects

Senior company executives in Brazil were among those arrested, police said. Brazilian authorities also asked U.S. police to issue arrest warrants for five more suspects in the United States.

A spokesman for Cisco in Sao Paulo declined to comment.

"We're studying, analysing all these events, everything that is being reported in the media, before we say anything or nothing to the press. Cisco is not going to comment on this," the spokesman said.

- Reuters