Thousands of people seeking donor insemination are being put on permanent waiting lists and told they will have to pay up to £1,000 a time because sperm supplies have been severely reduced by a change in the law which has removed donors' right to anonymity.

The first official figures from the government's fertility watchdog since the change in the law last April which removed UK donors' right to anonymity reveal that 18 men were cleared to donate sperm in April, 12 in May and 10 in June.

The traditional source of sperm, students keen to earn cash, has all but disappeared and some clinics, NHS and private, are turning away patients. Others have reported price increases from £200 a cycle a year ago to £700 because of the increase in the cost of sourcing sperm.

More recent figures are not available because of the time it takes to screen and approve donors. Some clinics are warning that recruitment is getting even harder after changes in the law at the beginning of the month under which donors from overseas lose their right to anonymity, all sperm donated before April 2005 must be used or destroyed, and donors can be paid only expenses.

Alan Pacey, secretary of the British Fertility Society, said the initial findings of a survey of clinics revealed rapidly depleting stocks. "The cost is going up, the supply is going down and waiting lists are growing. Patients are getting a raw deal," he said.

The Bath assisted conception unit has written to 20 patients to tell them it is suspending services, and St James's hospital in Leeds is not taking patients. Adam Balen, professor of reproductive medicine at Leeds, said: "The change in the law has decimated our donor service. Many couples are now being denied the treatment they so much desire ... I know that many couples are travelling overseas for egg and sperm donation."

William Ledger, of the centre for reproductive medicine and fertility at the Royal Hallamshire hospital, Sheffield, said: "In the past we've done matching of eye and hair colour. Not any more. Sperm prices have gone up fivefold in the last year. It's a seller's market and we have to pass the cost on to patients." He said a year ago the centre charged £200 a cycle; now it charged £700. Private clinics have charged up to £1,000. "Ordinary folk are being denied access as a result of the change in these guidelines," he said.

The Bridge clinic, one of the largest private suppliers in the country, has restricted supplies to other clinics. It says it has increased prices by 10%.

About 13,000 donor insemination cycles are carried out annually in Britain, and about one in 10 result in a birth. The Human Fertilisation and Embryology Authority has recorded dramatic drops in demand over the past 10 years as other treatments for heterosexual couples with fertility problems are offered.

The HFEA is warning that couples are being tempted by organisations on the internet. A spokesman said: "There are risks to the woman and child because there is no guaranteed screening, and a risk for the donor because, if you have unlicensed treatment, the donor is technically the father - the CSA could go after the donor, or the child could claim inheritance."