It is understood the confession box at Our Lady and St Etheldreda church, in Newmarket, is the first globally to be sponsored by a business.
Irish bookmakers Paddy Power paid £10,000 for the privilege of having its name on the new box – now called a sin bin – at the Catholic church.
Top jockey Frankie Dettori, who was married there, performed the official opening.
Last night, gambling support charity GamCare said it would be speaking with the priest in charge to find out more about the deal and said it would be concerned if the sponsored name plate did not also carry information about the support available for addicted gamblers.
Paddy Power – which has 200 betting offices in Ireland and almost 100 in the UK and a turnover of £2billion – only became involved after it was contacted by the priest at the church.
Father Michael Griffin said: “It was suggested by a parishioner that we asked Paddy Power for help because of their horseracing connections and we were very pleased when they generously agreed.
“We were happy to put a plaque up on the side of the box – which we refer to as a reconciliation room – and I have mentioned Paddy Power in a sermon.
“There has been no adverse reaction from anyone to the fact that the sponsorship has come from a bookmakers.”
Catholic diocesan spokesman Father Mark Hackson said: “There is nothing morally wrong with gambling unless it deprives people of what is necessary to provide for their needs and that of their dependants.
“We regularly raise funds through raffles and that is also a form of gambling. This money was freely given for a specific purpose and had been earned legally.”
Eileen Kinghan, Gamcare spokeswoman, said they would be trying to find out more about the deal.
She said: “We would be concerned if there were no signs for GamCare to raise awareness of the support available. We do provide counselling services in Newmarket.”
A Paddy Power spokesman said they were delighted to get involved due to their links with the racing industry.
He said: “We see it as a way of bringing the church to the people and forging stronger links between the church and local people.
“We hope that people might pop in to the church on their way to a race meeting here and perhaps their prayers will help them pick a winner.
“It’s a great fit and perhaps over time confessing your sins in a Paddy Power confession box will become a tradition for race-goers.”
Mr Dettori, who is riding the Guineas meeting in Newmarket this weekend, said: ”I was married in this church 13 years ago and all five of my children were baptised here. I am pleased that they are being helped by sponsorship.”SIC: EADT