Peter Kearney, director of the Scottish Catholic Media Office, made his comments in an interview on the current affairs programme "Scotland Tonight" on July 26.
"There is a link between same-sex sexual practice and early death. That's not something that the Catholic Church believes, there is an overwhelming body of medical evidence to suggest that. One study has shown that the life expectancy of a practicing homosexual man will be reduced by something between 12 and 20 years," Kearney said.
The spokesperson went on to say that there is a "conspiracy of silence around the vast array of medical evidence that exists to suggest that same-sex behaviour is hazardous, is harmful, and is dangerous".
"The wider question really is, as a society, why don't we debate that; why don't we have that discussion? Why don't we look at it in the same way, for example, that we've been happy to look at how smoking, how alcohol, how overeating, how drug addiction can cause harms to people's health?" he questioned.
Kearney went on the programme to speak after Bishop Philip Tartaglia, Archbishop-elect of Glasgow, suggested that the early 2011 death of Labour MP David Cairns could be linked to his homosexuality.
Tartaglia later apologised to Cairns' family.
Kearney went on to say that society was not taking a "compassionate" response by choosing to ignore the "complex infections, diseases and illnesses that are caused" by gay sex.
A representative from the David Cairns Foundation, which aims to support the same causes the late Cairns supported, came out shortly afterward to call Bishop Tartaglia's and Kearney's comments "scurrilous".
"David died in tragic circumstances due to complications arising from acute pancreatitis. A gallstone blocked his pancreatic tract leading to further infection acquired during the two months he spent in hospital prior to his death," a statement from the organisation read, according to STV.
"To suggest that his death was in some way connected to his sexuality is totally erroneous and made purely for political gain to somehow influence the debate on equal marriage," it continued.
"We take exception to the comments made by both Bishop Tartaglia, subsequently re-enforced by Mr Kearney in his television interview. Despite the half-hearted apology offered by the Bishop on Tuesday evening, Mr Kearney continued to support the Bishop's comments in a manner that we and many others would consider to be homophobic," it added.
The statement also suggested that in the future, faith leaders should take a more "considered and pastoral approach" to discussing homosexuality.
The issue of legalising gay marriage is currently a hot button topic in Scotland, with the country's religious leaders opposing such a measure. The government, however, plans to move forward with the legislation, it was revealed this week.