A man called to report his girlfriend's rape, only to get a dreadful question from police.

Trigger warning: This article contains information about sexual assault and/or violence which may be triggering to some readers.

A terrified boyfriend was mocked by police when he called to report that his girlfriend was being raped right in front of his eyes.

According to Metro UK, the 26-year-old man was camping with his 23-year-old girlfriend near Bonn in Germany in April this year when a stranger entered their tent and threatened them with a machete.

The woman was then dragged away and raped, while her boyfriend frantically called the police.

But when he told emergency responders what was happening, he was met with disbelief.

"Hmm. Where exactly is this rape happening?" the female officer reportedly answered.

The man hung up and waited for police to arrive to help them. But nothing happened.

When the attacker fled, the 26-year-old called police a second time as he walked along the main road with his girlfriend searching for help.

Their second response was more incredulous than the first.

"You are not messing with me, I hope?" the operator asked the man.

Almost 30 minutes later, police arrived and the woman was taken to hospital, where tests confirmed she had been raped.

A 31-year-old man was arrested in relation to the attack, after a walker recognised him from a police sketch. He was linked to the rape via DNA evidence, and a CD player he stole from the couple's tent was found in his possession.

A spokesperson for the Bonn Police confirmed a "major review" has been launched following the mishandled calls.

"[The] incoming official in the control centre, after our findings, did not initially correctly categorise the circumstances of the first call and react inappropriately in her language," Frank Piontek, a spokesman for the department said.

He added that the second call was also handled "incorrectly".

If you or someone you know is in need of help, please call the National Sexual Assault, Domestic and Family Violence Counselling Service on 1800 RESPECT.