The 24-year-old lock who has won 12 caps for the All Blacks was provisionally suspended after a sample tested positive for an unspecified substance on the World Anti-Doping Agency’s (WADA) banned list.

However, his B-sample has returned from Sports Medicine Research and Testing Laboratory (SMRTL), a US-based laboratory, and come back negative, meaning the ban has been lifted.

“This has been a challenging and difficult time for me, my partner, family and team-mates and I am grateful for their support,” said Tuipulotu.

“I’m pleased the matter is now closed, with my reputation and integrity intact and I look forward to getting back into training and an exciting year of rugby.”

Rob Nichol, chief executive of the New Zealand Rugby Players’ Association, said it was “unclear” why there was a discrepancy between the two samples.

“This is a matter that SMRTL is investigating and we look forward to their feedback,” he said.

“Working with Patrick through the process, we always felt confident that he would be cleared.

“To be honest, there is an element of frustration, given the initial result and publicity, but at least people now know Patrick did nothing wrong.

Last year, former All Blacks stars Dan Carter and Joe Rokocoko were cleared by the French Rugby Federation after an investigation into a possible failed drugs test while playing for Racing 92.

However, last month it was revealed the duo and Argentinian Juan Imhoff face a new probe into the matter with French Anti-Doping Agency investigating.