In front of me is a tall, muscular, tattooed man with a large scar on his jaw. He’s the British rapper, Professor Green – real name Stephen Manderson – and despite the tough guy image that goes along with his job, he has tears in his eyes and his voice is breaking. Manderson is discussing a subject that’s been called a silent epidemic. It kills more men under 45 than anything else and yet it’s something many of us feel uncomfortable talking about. It’s male suicide and Manderson knows more about it than most. Seven years ago, Manderson’s estranged father took his life, despite showing no previous signs that he was suffering.

In a heartbreaking documentary for BBC3, Manderson, who was raised by his grandmother in the London borough of Hackney, let the cameras in as he delved into his father’s past in an attempt to work out what led him, like so many others, to suicide. A common thread in his research is how many relatives and friends of men who have taken their own lives did not see it coming. Despite the devastating impact this has on the people left behind, families often brush suicide under the carpet. “The documentary was actually the first time me and my grandmother talked about it,” says Manderson. “It is difficult. It’s not something even family like to talk about. It’s really hard.”

It’s particularly difficult for Manderson. Just months before his father died, they were due to reconcile, but a phone conversation to make arrangements ended in an argument. His last words to his father were, “If I ever see you again, I’ll knock you out.” It’s a conversation he deeply regrets and since losing his father, Manderson has seen a therapist on a regular basis to deal with depression. He thinks more men should follow suit and look after themselves. Although suicide affects both genders, it is more common among men and the ratio of male to female suicide has shown a sustained rise over the last 30 years, according to mental health charity, Calm. In 1981, men accounted for 62% of suicides in the UK. By 2013, the figure was 78%. Suicide now accounts for nearly 5,000 male deaths a year, around three times that of suicide in women. Yet other big killers such as cancer and heart disease get far more attention.

“At the end of the day suicide is a violent end. It’s the taking of a life,” says Manderson. “It’s violent, irrespective of the method, so it’s hard to talk about and it’s scary. Shying away from it is not going to do any good, though.”

Stephen Manderson as a child with his father, Peter Photograph: BBC/Antidote Productions

Rory O’Connor, the professor who leads the suicidal behaviour research laboratory at Glasgow University, says the causes of male suicide are deep-rooted. “The bottom line is, we as men, are not socialised to seek help. We are traditionally the breadwinner, we’re the rock for our family.” As these traditional male roles have become more blurred over the past two decades, men are struggling to deal with that. “Currently services, arguably, are not set up for men to access them. Much better research needs to be done about why men clam up more and we need to go beyond the traditional cliches.”

Jane Powell, chief executive of Calm, hopes the documentary will kick-start a wider debate on men’s mental health.

“I think it’s a brilliant film but I would badly like it to be the start of a discussion about how life is for men. We have to give permission for men to say, ‘I don’t know how to go on’, and that not being a criticism of their gender because at the moment it is. For a guy to say ‘I can’t cope’ is to say ‘I’m not a man’ and I think that’s why it’s taken decades for the Department of Health and the media to tackle this.” Manderson challenges that stereotype, she adds. “[He] comes across as being so tough. When guys do tackle things like that, they don’t come across as being weak at all.”

Have any of Manderson’s fans been in contact since the publicity for the documentary started? Manderson’s voice shakes as he responds: “Yesterday, someone told me I had saved his life.”

If you are having suicidal thoughts, contact the Samaritans 24-hour helpline on 08457 90 90 90 in the UK. In the US, the National Suicide Prevention Hotline is on 1 800 273 8255. In Australia, the crisis support service Lifeline is on 13 11 14

• Professor Green: Suicide and me airs on BBC3 at 9pm on Tuesday 27 October.