All Blacks lock Patrick Tuipulotu has been cleared of doping and a provisional suspension lifted, the New Zealand Rugby (NZR) has said.
Tuipulotu was sent home from the All Blacks' end of season tour last November after testing positive for an unspecified banned substance. The team said at the time he had departed for "personal reasons".
NZR confirmed on Sunday after a local media report said the 24-year-old had tested positive for a specified substance, but said on Thursday he had been cleared following testing of his 'B' sample by an accredited laboratory in the United States.
"The test result is negative and, as a result, Patrick's provisional suspension has been lifted with immediate effect," NZR said in the statement. "He is now cleared to return to rugby immediately.
"World Rugby have been informed and has confirmed it will not be taking the matter any further."
New Zealand Rugby Players Association chief executive Rob Nichol said they were trying to determine why there was a discrepancy between the 'A' and 'B' samples tested by the Sports Medicine Research and Testing Laboratory (SMRTL) in Salt Lake City.
"This is a matter that SMRTL is investigating and we look forward to their feedback," Nichol said. "Working with Patrick through the process, we always felt confident that he would be cleared. At least people now know Patrick did nothing wrong."
Tuipulotu, who said on Sunday he had been 'shocked' by the positive doping result was pleased to have been cleared. "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," Tuipulotu said.
The lock made his All Blacks debut in 2014 and was in contention for the 2015 World Cup squad but underwent surgery for a congenital hip problem and missed most of the season. He returned to the national team last year but returned home early after playing his 12th test in the 68-10 victory over Italy in November.
* This article was amended on February 21st to reflect the fact that Tuipulotu's 'B' sample was negative