People harbour stereotypes about particular accents, and those judgements may be brought with them into the legal domain, the study stated.

These stereotypes, the researchers argued, could affect all parts of the system – from arrest to sentencing – and undermine not only suspects and defendants, but also the testimony of witnesses.

“Voices play a powerful role in the criminal justice system and police officers, lawyers and juries are all susceptible to judging voices based on stereotypes, whether they’re aware of it or not,” Ms Paver said.

“As things stand, listeners think some accents sound guiltier than others and we should all be concerned about that.”

The results showed that people with non-standard accents were more likely to be associated with criminal behaviour, but there was significant variation in perceptions between accents.

The RP-like accent was perceived as the least likely to behave in criminal ways – except when it came to sexual offences – while the Liverpool and Bradford accents were perceived as the most likely.

Ms Paver said: “The strongest connection we found was between people’s perceptions of class or status, negative traits such as aggression, and how they think someone is going to behave, particularly when it comes to crime.

“This is the first time that a concrete link between traits and behaviours has been made in the context of accent judgements.”

However, non-English accents, in particular Belfast’s and Glasgow’s, were rated significantly less likely to behave in criminal ways than almost all other accents.

They were also thought to be the most likely to “stand up for someone being harassed” – categorised as “honourable behaviour” – and least likely to exhibit “morally bad” behaviours.

Ms Paver added: “Our findings show that perceptions of speakers of regional accents and how status, social attractiveness and morality interact are much more complex than previously assumed.

“We need a much more nuanced understanding of how accents are evaluated when it comes to different crime types.”

The Ministry of Justice declined to comment on the study.