The latest PSNI officer recruitment campaign has attracted the lowest percentage of Catholic applicants for more than a decade.
The PSNI already has an under-representation of Catholics in its ranks and it is concerned the situation will worsen.
Fr Martin Magill said "the whole question of secrecy is something that needs to be tackled and I think there needs to be a willingness to talk about this publicly".
The PSNI currently has about 6,300 officers - 67% of whom as "perceived Protestant" and 32% of whom are "perceived Catholic".
New figures released by the organisation on Wednesday show more than 4,100 people applied to join the PSNI.
However, just over a quarter (27%) are from a Catholic background.
The figure of 27% is two percentage points down on the 2025 recruitment drive and the lowest since at least 2013, according to official police data.
The latest campaign ran for three weeks and closed earlier this month.
'Implications for the family'
Speaking to BBC Radio Ulster's Good Morning Ulster, Magill said someone recently told him: "I know more Catholics in Blue Lights, that's the television series, than I do in the police."
He added: "It really is more than anything else is being able to deal with some of the fear and the apprehension of actually what might happen and the impacts on families."
Magill is a parish priest at St John's parish on the Falls Road in west Belfast.
He said if "someone from the parish" wanted to join the police force, "that would have implications for the family".
"We need to build a different society where people in my parish could decide, 'no I want to join the police and it doesn't have huge implications, it doesn't have any implications'," Magill said.
"I think it does need the public conversations, we need to normalise this, that families don't have to talk about this almost in whispered tones that so and so has joined the police."
'Alarm bells'
Overall, 700 fewer people applied to join the force than last year.
Sinn Féin assembly member Linda Dillon told BBC Radio Foyle's North West Today that there were a number of "specific barriers" around police recruitment and denied her party has more to do to encourage younger people from a nationalist background to join the PSNI.
"If any political party went out and called for people to join the PSNI in the morning, to think there would be any significant increase in the number of applicants from any community is naïve in the extreme," she said.
She said that "legacy issue is a massive issue for the PSNI".
SDLP assembly member Colin McGrath said the lowest number of Catholic applicants to the PSNI in more than a decade "should signal alarm bells".
"Unless we see drastic changes things will only get worse, with Policing Board projections putting the number of officers from a Catholic background at just 23% in 10 years' time."
McGrath believes that 50-50 recruitment would "be a drastic action that for a period of time could be undertaken to try and secure the numbers so that they are re-balanced".
DUP assembly member Trevor Clarke said he does not think 50-50 recruitment should return, calling it a "discriminatory practice".
"I want to see people appointed on a merits-based system only, I don't believe we should have arbitrary numbers based on religion," Clarke said.
"This whole notion that these numbers need to be balanced is for the stars, to be honest.
"Because whenever I ask for the police, I do not ask: 'Can I have a police officer, preferably male, overweight, in his 50s? Oh, and by the way, he needs to be from a Protestant background'."
Ulster Unionist Party (UUP) assembly member Doug Beattie said that while the "legacy of the past" was relevant, it was also important that the PSNI can enter all schools to provide information on the organisation.
"Getting into schools and educating is a real bonus in regards to this, but they can't do that in some areas," he told BBC Radio Ulster's The Nolan Show.
Beattie said there are politicians who say the PSNI is "not welcome" to come to schools in their area for recruitment and information evenings.
"I think that's appalling," he said.
Chief constable Jon Boutcher, commenting on the recruitment figures, said policing is a role that "people can be quick to criticise, yet those very critics will always call us when they need help, and we will always be there for them whatever their background, culture or religion".
Background on the PSNI
In 2001, under policing reforms, the Royal Ulster Constabulary (RUC), which was overwhelmingly Protestant, was renamed the PSNI.
One of the aims was to build broader community support and increase Catholic officers.
Between 2001 and 2011 there was a 50-50 recruitment initiative which meant there was one Catholic recruit for every one person from a Protestant or other background.
Since then, there has been no legislation to address the issue.
Unionist politicians oppose its return.
The 50-50 process was introduced as part of the Patten policing reforms and was aimed at increasing the number of Catholic officers.
When it was first introduced, Catholics made up about 8% of the police.
Dissident republicans have murdered two police officers - Constable Stephen Carroll in 2009 and Constable Ronan Kerr in 2011, since the PSNI's formation.
Peadar Heffron, a Catholic PSNI officer, was seriously wounded by a dissident republican bomb, in 2010.
Det Ch Insp John Caldwell was seriously injured after being shot several times in a gun attack in 2023.