There is more than enough supply of sperm from redheads, at least as far as the world's biggest sperm bank is concerned.

Cryos, the world's largest sperm bank, told Ekstra Bladet newspaper its sperm bank's stores had more than enough supply of sperm from redheads so it is not entertaining redhead sperm donors even as 600 people are waiting in line to spread their genes.

Cryos director Ole Schou confirms that they had reached their peak capacity of 70 litres of semen from donors, and Cryos is now going to be more selective about who can donate.

"There are too many redheads in relation to demand," Mr Schou said.

"I do not think you chose a redhead, unless the partner - for example, the sterile male - has red hair, or because the lone woman has a preference for redheads. And that's perhaps not so many, especially in the latter case."

Cryos records show the only country in the world that seems to want redhead kids is Ireland.

Cryos is listed at the Guinness Book of World Records as the world's largest sperm bank. It even ships sperm samples to more than 65 countries. With over 140,000 samples available, Cryos assists in helping nearly 2,000 women each year.