Sky News found there were 185 recorded incidents of self-harm by asylum seekers in UK detention in 2010, compared to 409 in 2015.
The number of asylum seekers being held in detention centres increased from 25,904 in 2010 to 32,000 people last year, according to the Home Office.
Fr Peter Morgan, who serves in Liverpool, said: "I've known a number of people [seeking asylum] who've attempted to take their lives on a number of occasions.
"It's a hopeless place and you only see deportation at the end of it and the terrible fear that that brings with it."
Nagul Nadeson, an asylum seeker from Sri Lanka, has self-harmed and witnessed others self-harm in UK detention centres.
He said: "Probably the main reason is because your freedom's taken away.
"If you go there you don't know how long you're going to be there. There's no fixed date being set in detention - it could be weeks, it could be months, it could be years."
A Home Office spokesperson said: "Under the new adults at risk policy the appropriateness of the detention of an individual will be considered on a case-by-case evidence-based assessment."
According to the UN, at the end of 2014 there were around 1.8 million people around the world waiting for a decision on their asylum claims.
