A refugee from Ghana has been arrested on a charge of raping a woman at knifepoint as her boyfriend was forced to look on.

The couple were on a camping trip in the Siegaue Nature Reserve in the German city of Bonn when a machete-wielding man dragged the young woman from her tent at about 12.30am on 2 April.

He raped her next to the tent before running off in the direction of the River Rhine, said police.

The boyfriend, 26, had also been threatened by the man but later alerted police who released a photofit picture of the attacker.

Following a tip-off from a walker in Siegburg who recognised the man in the poster, police tracked down the 31-year-old suspect. He tried to evade arrest and threw a rucksack at one of the officers.

He was apprehended on Saturday (8 April) following DNA testing, Mail Online reports.

The woman was treatment in hospital after the attack.