The Canadian singer-songwriter died in his sleep in 2016, aged 82, after falling during the night at his Los Angeles home.
He was buried in his hometown of Montreal.
In an interview with CBC’s q, which airs on Monday, his son and producer Adam Cohen said he has been working on an unfinished collection of songs by his father.
Mr Cohen said: “I was tasked with finishing a few more songs of his that we started together on the last album, so his voice is literally still in my life.
“It’s a bizarre and delicious entanglement.”
The Hallelujah singer’s posthumous album is expected to be released next year.
Mr Cohen, who produced his father’s final album in 2016, You Want It Darker, said the new songs are “really beautiful”.
“To make a long story short, I believe that there are some really beautiful new songs of Leonard Cohen that no one’s heard that are at some point going to come out,” he continued.
Unlike the tracks on You Want It Darker, which reflected on death, he said the tone of this material “resembles his older work, something more romantic”.
Cohen’s final book of poetry, The Flame, will be released on 2 October, and includes previously unpublished poems and selections from his notebooks.
The singer, who didn’t launch his music career until the age of 33 in 1967, initially pursued a career as a poet and novelist during the 1950s and 1960s.
Cohen’s hit song Hallelujah, which was released on his 1984 album Various Positions, has been performed by around 200 artists in various languages.
His death came just three weeks after the release of You Want It Darker, which was his 14th studio album.
Following the release, he told The New Yorker magazine: “I’ve got some work to do. Take care of business. I am ready to die. I hope it’s not too uncomfortable. That’s about it for me.”