A former Danish gang leader died of gunshot wounds on Tuesday as his memoir on leaving the criminal underworld went on sale. He was shot a day earlier after an event to launch the book.

Nedim Yasar, 31, made a name for himself as a radio host after quitting Los Guerreros, a Copenhagen gang involved in the drugs trade. His book, "Roots", about pulling himself out of crime was published on Tuesday.

At least two shots were fired at Yasar when he was leaving the book launch on Monday by a gunman who fled the scene.

Danish justice Soren Pape Poulsen paid tribute to Yasar, who was born in Turkey and went to Denmark at the age of 4, according to newspaper Politiken.

"How sad and infinitely meaningless. I met Nedim once. I met a man who with all his heart wanted to create and new life and make a difference for others. My thoughts and compassion go to his friends and family," Poulsen tweeted.

According to news agency Ritzau, Yasar decided to leave his gang and join an exit programme after he learned he was going to become a father. He often spoke of his life experiences on his radio show.

Police said Yasar told them in 2017 he had been the victim of an attempted assault, after he had quit the gang.

Denmark had a record number of gang-related shootings last year, police said. Some politicians linked the rise in violence to problems integrating non-Western immigrants.