A group lobbying for changes to the organ donor system believes the number of families who overturn potential donors' wishes is higher than health authorities say.

The Organ Donor Service, which is funded by the Ministry of Health, says it is rare for families to veto a relatives' wish to donate their organs.

But the group Give Life says the service has admitted it does not know how many of the 40 percent of families refusing donation apply to people who wanted to be donors.

Spokesperson Andy Tookey says the service is deliberately misleading the government in order to keep the veto.

Mr Tookey believes many families are vetoing donors' wishes.

© NewsRoom 2006