Health officials have offered counselling to hundreds of cancer sufferers after sperm samples stored in an Edinburgh hospital were damaged by a faulty freezer.

It is understood six widows who had banked their husband's sperm at the Western general hospital are among those affected. Fertility support groups say they have been receiving calls from worried couples who had hoped to have children after radical treatment for various cancers.

Nearly 300 patients, many of whom were treated for testicular cancer, have been affected by the accident last July. The incident occurred through a fault with the liquid nitrogen supply to the freezer.

Over 24 to 48 hours the temperature rose from minus 190C to minus 53C. The fault was detected but officials have been criticised for not alerting patients immediately. The Lothian University Hospitals NHS trust revealed the problem at the weekend. Doctors say they cannot rule out the possibility that the sperm could be useless for conception or lead to fetal abnormalities.

Euphemia McGoogan, the associate medical director at the trust, said staff were devastated at the anxiety caused to patients already struggling against cancer.