All Black Patrick Tuipulotu has had his doping charge dropped after his B-Sample came up negative for banned substances.
The lock is now clear to continue training with the Blues, after he was provisionally suspended in November followed a failed drugs test.
In a statement, Tuipulotu said it's been a rough couple of months.
"This has been a challenging and difficult time for me, my partner, family and team mates, and I am grateful for their support.
"I look forward to getting back into training and an exciting year of rugby."
New Zealand Rugby Players' Association boss Rob Nichol said there is no information as to why Tuipulotu's A-sample tested positive.
He said they were always confident Tuipulotu would be cleared, and that it was a frustrating time for the lock given the publicity of the initial result.
Nichol believes Tuipulotu was unfairly labelled as a result of the A-sample result being leaked to the media.
"This is a matter that (the laboratory) is investigating and we look forward to their feedback."
NZR chief exceutive Steve Tew welcomed closure on the case.
"This is an important and welcomed conclusion for both Patrick and for rugby. We are pleased that a robust process has been undertaken, and that he has been fully cleared.
"There is no room for doping in rugby, and we take our responsibility to keep the game clean very seriously," he said.
Tuipulotu will rejoin the Blues camp in preparation for the upcoming Super Rugby season.