Australian photojournalist Warren Richardson has won the World Press Photo of the Year award for an arresting, black-and-white photo of a man passing his baby through razor wire across the border from Serbia into Hungary. 
Richardson, a freelance photographer living in Budapestspent five days at the border while at least 20,000 people from countries including Syria, Iraq and Afghanistan crossed into Hungary.
Taken at night on    August 28 last year, the man and child were among the people seeking to cross into Hungary before a secure fence on the border was finished.
Richardson had been with this group for about five hours, playing cat and mouse with the police the whole night, he says in statement to World Press Photo, the  organisation behind the award.
"I was exhausted by the time I took the picture.
"It was around three o'clock in the morning and you can't use a flash while the police are trying to find these people, because I would just give them away.
"So I had to use the moonlight alone."
The power and simplicity of the photo drew the judge's eye, especially the symbolism of the razor wire, and its documentation of one of the defining moments of the refugee crisis in 2015.
On his blog, Richardson wrote about a night he will "never forget" when he saw a group of Syrians hiding among apple trees on the Serbian side of the border (it is not clear if this is the same night his winning photo was taken).
Among them were a group of engineers intent on figuring out the best way to breach the fence and let people through, who played a game of "cat and mouse" with the Hungarian police.
Each time the frustrated police returned they tried to fix the fence, but when they left the hole would be reopened.
"The police were yelling into the darkness in broken English, 'Do not come illegally into Hungary, go away we do not want you here, if we catch you, you will be arrested," writes Richardson. 
Over four hours the group of engineers helped more than 200 people go under the razor wire fence, and then said goodbye to Richardson before going into the darkness of the night. 
The 2016 World Press Photo contest drew entries from around the world: 5775 photographers from 128 countries submitted 82,951 images. You can see them here.
Richardson, a self-trained photographer, has also documented the movement of refugees further into Europe, and was beaten by the police while covering the crisis. 
His next project will see him walk to the Arctic Circle, to cover refugee stories and explore the effects of human-induced climate change on the world, he writes on his website.