Iran’s student news agency ISNA reported on Saturday that the prosecutor’s office, which made the revelation in a statement, gave no details of the identities of those involved.
The five are being held in custody while the inquiry continues.
Journalist Zahra Kazemi died earlier this month of a brain haemorrhage due to a yet unexplained blow to her head received while she was in custody in Tehran. She was arrested for taking unauthorised photographs outside a prison.
Canadian officials said they have not received any official confirmation whether anyone has been arrested in connection with Kazemi’s death.
But a Department of Foreign Affairs spokeswoman said Ottawa would welcome these developments if confirmed.
Ebb in relations
Khatami has ordered the Justice
Ministry to find those responsible
The incident has created strains in ties between the two countries.
Ottawa recalled its ambassador in the Islamic Republic after Iran refused to repatriate her body to Canada. Kezami was buried in her home city of Shiraz but Canadian officials continue to demand her body’s return and for those responsible to be put on trial.
Meanwhile, Iranian Foreign Ministry officials on Saturday lodged a formal protest with the Canadian embassy over what Tehran says is the “murder” of a young Iranian in Vancouver.
Keyvan Tabesh, 18, was shot dead by Canadian policemen on 14 July after he charged at an officer with a machete following another incident in which he attacked a car, said Canadian officers.
Foreign Minister Bill Graham promised a full, transparent investigation into the incident, offering Iranian officials the opportunity to be present.
Iran’s Foreign Minister Kamal Kharazi on Friday dismissed Canada’s account of the youth’s death as “incomprehensible” and called on Ottawa to provide a “convincing explanation” of how he died.
Graham refused to compare the deaths of Kazemi and Tabesh but called on Tehran to reciprocate with a transparent and open investigation into the journalist’s killing.