Photos of the bird were sent to Mr McKinlay earlier this week by Waimate man David Chamberlain.
Mr Chamberlain said he had first spotted the bird at his holiday cottage just after New Year and it had visited several times a day for a few days after that.
''I thought `oh, that is unusual' and then further inquiries revealed that it is actually quite unusual.''
Mr McKinlay said he had talked to his scientist friends but no-one had ever heard of a white fantail before.
He said a family of four white pukeko were seen on a farm in the lower Waitaki in 2011, a white yellow-eyed penguin was spotted once in the Auckland Islands and, in Dunedin, a colourless kereru (wood pigeon) had been seen.
White blackbirds were most commonly seen, Mr McKinlay said. They were not albino though; the phenomenon was caused by ''proteins failing in the colour scheme'', he said.
''It can happen in any animal. (Project Kereru founder) Nik Hurring had a kereru that didn't have any colour. It didn't go white, it just didn't have any colour.''
Mr Chamberlain said Te Papa museum now had his photos on their website but he would try to get better images next time he was at the lake.
''I will be keeping my eye out to see if it survived.
''Hopefully I don't see a pile of feathers under a hawk.
''They don't like flying in open country and we do have hawks up here. Certainly, it stands out, too. It is lucky to have survived.''
He guessed he was at the northern boundary of the corridor that the bird used to feed because there were no trees further north.