A London charity that supports male victims of rape has been given £78,000 funding by the mayor's office.
Survivors UK said the money, over three years, will allow it to reach out to more victims to make them aware of a "safe space where they can get help".
Paul Scates, a sex abuse survivor, said the charity gave him "validation" and was "like a fourth emergency service".
Conservative London Assembly member Kemi Badenoch, who lobbied for the funds, said the "taboo" needs tackling.
A report called Silent Suffering, published last November by Ms Badenoch, estimates about 92,000 rapes and sex attacks were not reported to Met Police between 2010 and 2014.
Chief executive of Survivors UK, Keith Best, said the funding signifies a genuine need for support for male victims.
'Part of a joke'
"We are only seeing the tip of the iceberg," he said.
"What we are seeing is that in many institutions, like schools, prisons and care homes, sex abuse is a potential problem."
The abuse has an "enormous knock-on effect" with post-traumatic stress, feelings of shame and guilt which leads to breakdown in relationships.
Mr Best said the charity had received £52,666 since 2012, but the funding was coming to an end in April. He now wants to develop its work in prisons.
"It is part of a joke in some cultures, particularly in male-dominated institutions," he added.
"We want to enable survivors to realise that there is a safe space where they can come and get help."
'Scars remain forever'
Mr Scates was abused from the age of eight until 16 by a "charismatic" married man who was introduced to his family by a relative.
"He groomed my family and me for three years before getting physical. It stopped when I tried to end my life."
Mr Scates said he was "lucky" to get therapy from the NHS and found Survivors UK three years ago.
"Wounds heal but scars remain forever. When you are abused it is like a life sentence and you live with it but with support you go from being a victim to a survivor," he said.
Ms Badenoch said: "Male rape is a rarely mentioned taboo.
"No victim of rape or sexual assault should feel they have nowhere to turn and be made to suffer in silence."