Eleven of the deficiencies must be fixed before the ship's planned departure at midday today.
Steve Rendle, senior communications and media advisor for Maritime New Zealand, said the deficiencies indicated poor management and a lack of resources.
The number of deficiencies could be considered "pretty serious", he added.
Mr Rendle said the vessel would be inspected again in the morning to ensure the deficiencies were rectified.
Mediterranean Shipping Company New Zealand operations manager Mike Hodgins said the company had hired the Vega Auriga to go through Australia, Noumea and New Zealand.
However, the recent developments meant the contract ended when the cargo was unloaded in Tauranga on Sunday.
"We've off-hired it because it couldn't do what it was supposed to do," he said. "Australian Maritime Safety Authority (AMSA) has said it's not allowed back in Australia for three months at the moment which was what it was supposed to do."
Mr Hodgins said the decision to end the contract was nothing to do with the deficiencies found in Australia or New Zealand.
"It was given an all clear when it left Sydney, when it left Australia. It had been declared it was okay."
Judea's Mary Sanson volunteered to help clean the beaches after the Rena grounding.
She said she was glad the ship was being closely monitored while in Tauranga and hoped all the problems were fixed before it sailed again.
"It's better to have it where we can see what it's doing and keep an eye on it - and make sure it doesn't leak anything."
The Vega Auriga was banned from Australian ports for three months on Wednesday. It had been detained three times in Australian ports since July last year and was declared "unseaworthy and substandard".