A gay married couple is suing a Massachusetts Catholic diocese alleging that the religious group declined to sell the couple a property because of their sexual orientation.

The two men were negotiating to buy the Oakhurst Mansion in Worchester County until the deal abruptly ended, the couple says.

While trying to purchase the 44-bedroom mansion the "owner of the property, refused to sell the property to them after discovering that the two men are gay and married, and that they would allow gay marriages to take place," the couple's lawyers said in press release Monday.

Alain Beret and Jim Fairbanks allege in the lawsuit that they made a $75,000 down payment and invested thousands of dollars for inspections before the Roman Catholic Diocese of Worcester walked away from the deal.

James Gavin Reardon Jr., the attorney representing the diocese said discrimination had nothing to do with the failed deal.

"The diocese doesn't believe it's discriminated against gay people and will prove that in court," said Reardon. "There was no purchase and sale agreement with the buyers. Their financing fell though ... The diocese never knew and never asked about the potential buyers' sexual orientation."

But the couple alleges that they have an e-mail chain sent from the diocese's broker that tells a different story and shows that the diocese was aware of Beret and Fairbanks' sexual orientation.

According to the lawsuit, the e-mail chain contained a message from a leader in the diocese who said: "because of the potentiality of gay marriages there, something you shared with us yesterday, we are not interested in going forward with these buyers. I think they're shaky anyway. So, just tell them that we will not accept their revised plan and the Diocese is making new plans for the property. You find the language."

The couple said they were concerned when they were mistakenly sent the e-mail.

"All I can tell you is the blood rushed from my head in total disbelief. Here we are in the 21st Century in Massachusetts and we're experiencing this kind of discrimination," Beret told CNN affiliate WHDH.

In the lawsuit, filed Monday in Worcester Superior Court , the couple is seeking a jury trial and unspecified punitive damages.

Before the Oakhurst Mansion became the subject of this lawsuit it was called the House of Affirmation and used as a treatment facility for pedophile priests, WHDH reported.