Egg and sperm donors could be paid in a move designed to halt the number of infertile couples travelling abroad for treatment, the head of the Human Fertilisation and Embryology Authority has said.

Professor Lisa Jardine said that a shortage of donated sperm and eggs was driving childless couple to become "fertility tourists".

The problem is so acute, said the chairman of the HFEA, that consideration should now be given to dropping the ban on payments.

Such a step, however, would raise serious ethical questions about the motivation of donors and the potential impacts on the children born from paid donations.

Until now, despite some patients getting money-off deals for IVF treatment, donors in Britain have been able to claim an element of altruism. In countries where payments are legal, such as the Czech republic and Spain, egg donation has been used by women as a means of paying off debts.

A shortage of donations, which worsened when anonymity for donors ended in 2005, has meant many childless patients have to wait years to receive them and is the prime reason for rising numbers of couples seeking treatment abroad.

A spokeswoman for Professor Jardine said last night: "Payments are something she feels we need to look at."