An Italian man and his Canadian companion abducted last December in Burkina Faso are alive but may have been moved to another country, a Burkinabe government spokesperson said.

An Italian missionary abucted last September in Niger meanwhile may since have been briefly held in Burkina Faso, the spokesperson added.

Burkina Faso's government spokesperson Remis Fulgance Dandjinou updated Italy's state television channel Rai on the hostages in an interview broadcast on Friday evening.

They information they had on Luca Tacchetto, 30, and 34-year-old Canadian Edith Blais suggested that they were no longer in Burkina Faso, he said.

But he added: "We are certain that their life is not in danger. We can say that these people are still alive."

Quebecois Blais and Tacchetto, from Venice, disappeared mid-December when driving through Burkina Faso.

Armed men abducted Father Pier Luigi Maccali, 57, from his home in southwest Niger in September.

While denouncing the abductions, Dandjinou added: "The important thing is that there has been no homicide, otherwise we would have already recovered the bodies."

A Canadian geologist abducted in January from a mine in the northwest of Burkina Faso was found dead the following evening.

The country has been prey to a wave of abductions and since 2015 has also had to contend with deadly attacks by jihadist groups.

Meanwhile Italian investigators looking for Silvia Romano, a 23-year-old volunteer at an orphanage in Kenya said after talks with officials in Nairobi that they were certain she was still alive, the Italian daily Corriere della sera, reported on Saturday.