Berlin’s police force is facing considerable embarrassment over the arrest of a woman who has repeatedly posed as a police officer and claims to have helped them apprehend criminals.

The woman, identified only as ‘K’, was arrested a week ago wearing an authentic uniform and carrying equipment apparently belonging to the police.

The 22-year-old was spotted by police officers who admitted that the woman looked suspicious because she was dressed in an entire uniform including a jacket, despite the summer heat.

“That was my mistake,” K said in her first interview, with the Berliner Morgenpost newspaper.

The woman has already spent 14 months in prison after being convicted for unauthorised assumption of authority.

Despite the conviction and her recent arrest, when amphetamine was also found on her, she said she is determined to continue to pose in the role. “I still want to continue ... because I want to help people,” she told the Berlin daily. “I don’t have any bad intention.”

She also has a previous conviction for sexual abuse, she said, without giving details, but adding: “That is the reason I’m not able to work as a policewoman.”

There has been a reported rise in the number of fake police in recent years. Tourists visiting Berlin are warned to be aware of tricksters who pose as police and ask to search tourists’ bags before stealing wallets and phones. In February this year, dozens of German-speaking Turks were arrested in Turkey after posing as police officers who telephoned German pensioners and relieved them of hundreds of thousands of euros after they were persuaded to reveal their bank details.

K claims to have helped real police officers apprehend criminals and break up fights. She cited a fight in Berlin’s Alexanderplatz in April in which hundreds of young men arrived to defend two feuding YouTubers, which triggered a large police callout. K claims to have helped the police take down details of those apprehended.

She also claims to have accompanied the police in their vehicles on more than one occasion. It has not been possible to verify any of the details.

The Berlin police force has so far refused to comment on the case, other than to say that a woman has been arrested and her uniform seized. But it is coming under pressure to explain how it was possible that K was in possession not only of an authentic uniform but also a truncheon, handcuffs, pepper spray, a fake weapon and police insignia and badge. She claims she paid between €3,000 and €4,000 for the items.

K said she had often been caught, but was now so well known to the police that they would often let her go with just a verbal caution.