A Maritime New Zealand spokesman for the oiled wildlife centre in Tauranga said they had received a box of the handmade sweaters and that should be more than enough.
"The vets have expressed appreciation [but] they haven't used any," he said. "They haven't been required and I just don't know that they will be used at all."
A keeper at Auckland Zoo said the idea of making the little birds wear the jerseys might cause them extra stress.
Natalie Clark, New Zealand bird and mammal keeper at the zoo, who has recently finished a four-day stint at the Te Maunga oiled wildlife centre helping care for birds affected by oil from Rena, said the woollen concept was new to her.
"When I was down there [at the Tauranga wildlife centre] they certainly weren't using them."
She said the cleaning process strips the birds of their natural oil and can make them cold but the facilities at the centre were set up to cater for this. "They are getting washed and rinsed and then they go into a warmed tent under heat lamps."
She says there are also portable dryers which are stationed over the birds to dry and warm them.
"At this time of the year it's quite warm. Once they've been washed and rinsed they don't really need anything else to keep them warm," she said.
The oiled wildlife centre currently has 288 live birds in care and 223 of those are penguins.
Miss Clark said she had never seen a vest on a penguin and she wondered how much the birds would appreciate the costuming.
"Putting something like that on a penguin, it's probably only going to stress it out even more than they already are. These are wild penguins, they haven't had any interaction with humans. There's already enough stress on a bird without trying to put a sweater on it," she said.
Maree Buscke of Skeinz.com, which helped to organise the knitting scrum, said the sweaters were a way for people to help, even if they weren't going to be used. She was still receiving sweaters from knitters, she said, plus turning down more offers to help.
"We sent up a huge group to them. We sent up about 120. [But still in the office] it's up into the hundreds and could be into the thousands. It's really captured people's imaginations," she said.
It has been reported the knitted sweaters have been used after oil spills in Australia. The sweaters could be used to cover penguins, keep them warm and make sure they don't preen themselves and ingest the toxic oil. An Australian group has already contacted Ms Buscke and will take any excess sweaters.
The oiled wildlife centre has asked no more woollen penguin sweaters be sent to it.