LONDON, Nov 16 (Thomson Reuters Foundation) - Women and girls around the world face "50 shades of violence", ranging from rape and sexual harassment to acid attacks and forced marriages, and men need to do more to stop this, a former British chief prosecutor said on Thursday.

Nazir Afzal, a former Chief Crown Prosecutor for England's northwest region, has prosecuted some of the highest-profile cases of sexual abuse in Britain, including gangs that "groomed" vulnerable young girls for sex slavery.

He said the level of violence against women and girls in every country was rampant and not enough is being done to stop this with more convictions needed to ensure justice for victims.

"There are 50 shades of violence against women and girls," he told the Thomson Reuters Foundation's annual Trust Conference, which focuses on slavery and women's empowerment.

"There is no community where women and girls are safe ... too many families think that a boy is a blessing and a girl is a burden."

Worldwide a third of all women experience physical or sexual violence at some point in their lives, according to the United Nations.

An estimated one in five will be a victim of rape or attempted rape, with high rates of femicide and domestic abuse gripping many countries.

"We have got to shed a light on this kind of behaviour," said Afzal, who quit as head of the Association of Police and Crime Commissioners this year in a row over media coverage of Britain's Manchester terror attack that killed 22 people.

Afzal, who now advises the UK government and trains lawyers and judges from other countries, said gender violence was fuelled by misogynist attitudes that view girls as inferior and less capable than boys, while condoning abuse against them.

"Too many men think they can get away with it - and too many men do get away with it," Afzal said.

"The answer again goes back to tackling the root causes of all this behaviour and the root causes are clearly patriarchy and misogyny ... we have to recognise that this issue is all about power and control."

Afzal said the string of sexual assault allegations against actors in Hollywood showed that men and women are treated and judged differently when it comes tackling sexual harassment.

"When a woman makes an allegation against a celebrity ... (they are asked) what were you wearing, what were you doing in that room, why didn't you report it," he said.

"That is misogyny, that is patriarchy and that is the obstacle we have to overcome."

(Reporting by Anastasia Moloney @anastasiabogota, Editing by Belinda Goldsmith; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights, climate change and resilience.