OTTAWA (Reuters) - Canada has imposed sweeping restrictions on who can donate organs for transplant -- including a ban on gay men who have been sexually active in the past five years -- and a leading doctor said on Tuesday he feared the move could deter potential donors.

The restrictions, which also cover drug addicts, prisoners, prostitutes and people who have had tattoos or body piercings in the last 12 months using shared needles, came into effect last month.

“The safety of the cells, tissues and organs intended for transplantation is paramount. These regulations are based on risk for safety purposes and not lifestyle choices,” said a Health Canada spokeswoman.

The rules include a loophole that allows doctors to use healthy organs from a person in a high-risk group as long as they first inform the patient receiving the transplant.

The head of Canada’s largest organ transplant program -- operated by the University Health Network in Toronto -- said doctors had already been following many of the same rules, which are similar to regulations that govern blood donations.

But Dr Gary Levy said he feared some people might wrongly decide they were in a high-risk group and decide not to make their organs available for donation.

“I’m worried about (whether) this will have a negative impact on organ donation ... I was on a radio show today and someone called in and said ‘I can’t donate’,” he said.

“I said ‘That’s not true ... leave it to the professionals to determine whether these organs can be used safely and if they’re good’,” he told Reuters, saying the regulations should have focused more on risky behavior.

“If you have a same gender partner and you’ve had that same gender partner for 30 years, you’re not a high-risk group. But if you’re a heterosexual and you went out and had sex with 14 people last night, you’re a high-risk person,” he said.

Helen Kennedy, executive director of the gay rights group Egale Canada, described the regulations as outrageous and crazy.

“It’s perpetuating stereotypes. It bans every gay or bisexual man who potentially is in a monogamous relationship -- or other gay men who are vigilant about safe sex practices -- from donating organs,” she told Reuters.

“The question should be based on behavior: Have you had unprotected sex with anyone ... or, have you had unprotected anal sex?”

Health Canada insisted gay men were not being singled out.

“A gay man who had practiced abstinence for the five years prior (to making an organ donation) would be acceptable,” said the spokeswoman.

“Likewise a heterosexual man who had had a single sexual encounter with a male within the last five years would not be considered acceptable even though he is not gay.”