WELLINGTON (AFP) - New Zealand women's sevens player Lavinia Gould has been banned for two years after testing positive for a banned stimulant, officials said Friday.

The International Rugby Board imposed the ban after tests conducted at an international sevens tournament in Dubai found the stimulant methylhexaneamine in Gould's system.

New Zealand Rugby Union chief executive Steve Tew said the substance was in a dietary supplement that Gould had taken, even though it had not been approved by medical staff.

"We are very disappointed this has occurred," he said in a statement.

"We have invested heavily in education to ensure players understand their obligations and the risks around taking supplements."

Gould's suspension was backdated, meaning she will be eligible to play again in January 2015.