Cristiano Ronaldo said that has no regrets after making an intimate documentary about his life and career at the launch on Monday.

Made by the team behind award-winning films about Ayrton Senna and Amy Winehouse, 'Ronaldo' charts the Portuguese ace’s life between Real Madrid's European Cup triumph in 2014 and his third Ballon d'Or crown in January 2015.

The film's revelations include a confession by Ronaldo's mother, Dolores, that she wanted to abort him, while Ronaldo talks openly about his brother and late father's struggles with alcoholism.

He also defends his decision not to disclose the identity of his son Cristiano's mother, but when asked if he felt he had opened up too much, the Madrid superstar replied: "Maybe, but I just had fun. I don't regret anything. I feel unbelievable. When you do something, people will find reason to criticise you. But it’s normal. Since I was a young boy I always felt special. I saw that people looked at me with different eyes."

The film captures intimate moments at home between Ronaldo and his five-year-old son - whom he dubs "my successor" - and shows him relaxing with friends including his agent, Jorge Mendes.

The Portugal captain, 30, discusses his obsession with winning the Ballon d'Or, which he has won for the past two seasons after seeing his great Barcelona rival Lionel Messi walk away with it for the previous four years.

"I've started seeing him as a person, not a rival," Ronaldo says of the Argentine. "But we are always competing to see who is better."

On speculation about the identity of his son's mother, Ronaldo, who describes himself in the film as an "isolated person" with few friends in football, says, "I've never told anybody and I never will."

Ferguson promise

Asked why the film does not feature Irina Shayk, the Russian model whom he split from last January, Ronaldo said it was because the filmmakers "didn't see a strong part to put in the movie".

He also refused to be drawn on the crisis surrounding suspended FIFA president Sepp Blatter, who is pictured in the film during scenes shot at various Ballon d'Or galas.

"When Cristiano says something it's a huge thing. I'm not going to be involved in these problems," Ronaldo said. "What do you expect me to say?"

The film also reveals that a promise by former Manchester United manager Alex Ferguson that Ronaldo would play in 50 percent of the club's games prompted him to move to Old Trafford in 2003.

Mendes says that Ferguson's offer was key in encouraging the winger, then an 18-year-old rising star at Sporting Lisbon, to reject rival offers from clubs including Barcelona and Inter Milan.

Speaking on Monday, Ronaldo said: "When Sir Alex Ferguson says, 'Cristiano, I want you to come to Manchester United, you're going to play 50 percent of the games,' it made me feel comfortable and I said, 'Wow.'

"Because at 18 years old, to play 50 percent of the games, for me it's unbelievable. Jorge helped me to take that decision and of course the last word of Sir Alex Ferguson was the key to sign for Manchester United."

Ronaldo spent six years at United, winning three Premier League titles, the 2008 Champions League and being awarded his first Ballon d'Or, before joining Madrid in a world-record transfer in 2009.

He has won La Liga, two Spanish Cups and the Champions League at Madrid and last month became the club's record goal-scorer. His current Madrid tally stands at 326 goals in 315 games.

The film was due to have its official premiere at a London cinema later on Monday.