The donors affected were those who usually give between £3 and £5 a month by direct debit. Instead, a decimal point error meant they were charged 100 times that amount.

When Greenpeace was alerted to the error, it notified the banks and the affected supporters had their money returned. A statement on its website apologises for the problem and says any bank charges incurred will also be refunded.

If you were affected by the computer glitch, please contact Greenpeace on 0800 269 065 or by email at supporter@uk.greenpeace.org