One in every ten nightclub bouncers and security guards who applied for a licence to work over the past three years has had their application refused, with many failing to supply details of previous criminal convictions in other countries.

According to latest figures released by the Private Security Authority (PSA), this means that more than 4,700 people who may have already been working in security for years have now had their applications refused since licensing began in 2007.

However, although more than 5,400 people – or 15% of people vetted so far by gardaí – were found to have a criminal record, only 127 of those applying had their application refused for this reason.

The PSA says this is because, in the "vast majority" of cases, a person's previous convictions were not deemed to be relevant to their licence application. For example of the 5,437 recorded convictions, it notes that 2,391 related to motor offences where only a fine was imposed.

"In 358 cases, the authority wrote to the applicant regarding the conviction. The main reason for writing to an applicant is because the authority deems the conviction relevant to the issue of a licence or the applicant failed to disclose the conviction on the vetting form," a spokeswoman said. "127 cases resulted in the application being refused because the conviction was relevant or because the conviction was not disclosed."

Meanwhile, the PSA has revoked 14 licences previously issued to people working in the security sector, typically as security guards in shopping centres and office buildings, and as doormen in pubs and clubs.

Among the reasons for this are where an individual was found to have provided false information about their identity, or went on to be convicted in court for an offence deemed relevant to their job, such as public order offences and assault.

A total of 206 people have also been issued with a formal warning by the PSA; it says in most cases this was because licensees were found to be not wearing their ID badge or carrying their PSA licence.

"The wearing of the identity badge is central to the licensing of individuals as it ensures that the public know that an individual is trained and licensed. It also serves as identification in the event that a member of the public wants to make a complaint against an individual," the PSA spokeswoman said.

Overall, the number of people working in security has fallen by more than 30,000 to 23,579 since last December, a trend which the PSA says partly reflects the economic environment.

"The authority expects this figure to contract further as licence-holders let their licences expire. The renewal rate stands at 62%", the PSA spokeswoman added.