Louis Guay, left, and Robert Fowler had long beards when they made a public appearence in the Malian capital, Bamako, a day after their release. (Harouna Traore/Associated Press)

Freed Canadian diplomat Robert Fowler returned to his Ottawa home on Tuesday.

The Ottawa Citizen photographed Fowler arriving at his house shortly before noon in a black Mercedes van with tinted windows.

Fowler, a United Nations special envoy to Niger, and his assistant, Louis Guay, were kidnapped in Niger on Dec. 14. They were held for four months before being released by their abductors in neighbouring Mali on April 22.

A Canadian official told CBC News that Fowler and Guay weren't physically harmed in captivity, but they did suffer psychological torture. Both looked healthy and sported long beards when they were released.

The Prime Minister's Office last week said Fowler and Guay would be flown back to Canada on government aircraft.

Kidnapped after touring a mine

Fowler and Guay were returning from a trip to a Canadian-operated mine in Niger with their UN driver, Soumana Moukaila, when they were abducted. Their vehicle was found the same day, abandoned in good working condition about 40 kilometres northeast of Niger's capital, Niamey.

Moukaila was freed in March.

Al-Qaeda's North African branch, known as AQMI, has claimed responsibility for the kidnappings.

Prime Minister Stephen Harper has denied Ottawa paid any ransom to secure the Canadians' release.

He also stated Canada did not make any promises regarding militants being held prisoner. However, he did not explicitly rule out the possibility that Burkina Faso and Mali, the two countries that helped secure the release, might have done so.