France's last hostage returns home celebrating freedom

His freedom was nearly three years in the making ... but France's last remaining hostage abroad is finally home on French soil.

Serge Lazarevic had been kidnapped by Al Qaeda's North African wing in Mali in 2011.

He arrived on Wednesday to the warm embrace of French President Francois Hollande.

(SOUNDBITE) (French) FREED HOSTAGE, SERGE LAZAREVIC, SAYING:

"Being a hostage is a bit complicated, it's not very simple. But the journey back to my freedom is beautiful. I had forgotten what freedom was."

But amid the hugs ... questions linger over just the how the 50-year-old engineer came to be released.

There were reports of a prisoner exchange and possible ransom.

France dispatched thousands of French troops in Mali last year ... to scatter Al Qaeda militants in the former French colony.

But it's had to rely on a network of negotiators to secure the release of a number of French hostages held in the region.

(SOUNDBITE) (French) FRENCH PR