Evil Ireland, 56, even asked to be allowed to attend Friday prayers but was turned down.
The killer, who slaughtered five gay men, is now determined to convert to Islam from Christianity.
He told fellow inmates at Wakefield jail, West Yorkshire, his change of faith was sparked by spicy food.
A source said: “A love of curry must be the strangest reason ever to want to convert.
“Ireland really loves the vegetarian mushroom curries that are prepared mainly for the Muslim inmates in the prison.
“In his mind, the quality of the food has somehow got mixed up with Islam and the Muslim faith.”
The former soldier, who is caged on B-wing of the jail, put his name down for Friday prayers two weeks ago.
But governors rejected the application because he is a non-Muslim.
They think Ireland wants to convert for a cushy life.
Our source added: “They think Colin just wants a better lifestyle and this has little to do with religious beliefs. He can’t believe how much better the food is for Muslim inmates.”
In June, Dame Anne Owers, the Chief Inspector of Prisons, wrote that some inmates had been converting to Islam to gain extra perks and protection.
All prisons offer a Halal menu, which some inmates regard as being better than the usual dishes on offer.
Muslims are also excused from work and education while attending Friday prayers.
In the report, one inmate, dubbed a “convenience Muslim”, is quoted as saying: “Food good too, initially this is what converted me.”
Ireland decided he would become a serial killer in a sick New Year resolution in 1993.
He tortured and killed the gay men he pretended to befriend.
Ireland was caught when he was identified by CCTV footage with his last victim. He confessed to having committed all five murders.
He was jailed at the Old Bailey in December 1993.
The judge at his murder trial, Mr Justice Sachs, said Ireland was “exceptionally frightening and dangerous”.
He is one of only 35 prisoners to have been given a whole life tariff by a Home Secretary.