WADA had partially suspended the Laboratory in the American city back in June but they did not specify the reasons why.

During the suspension, the UCLA Laboratory was able to continue carrying out all of its regular anti-doping activities but had to gauge another opinion on the four substances.

The facility is now no longer required to obtain a second opinion prior to reporting Adverse Analytical Findings for the four specific prohibited substances as a result of WADA lifting the partial suspension.

WADA's Laboratory Expert Group recommended to the body's Executive Committee that the partial suspension be lifted on September 27 and the decision was approved by President Sir Craig Reedie.

"WADA is pleased to confirm that the UCLA Laboratory's accreditation has been reinstated approximately three months after the Laboratory was partially suspended," WADA director general Olivier Niggli said.

"We commend the UCLA Laboratory for their quick and effective response in addressing the issue that led to the partial suspension.

"Athletes can be confident that the Laboratory is operating at the high standards required by WADA and the global anti-doping programme."

Founded in 1982 after a grant from the Los Angeles 1984 Olympic Organising Committee, the UCLA facility was the first American Laboratory accredited by the International Olympic Committee.

Don Catlin formed the Laboratory and served as its director for 25 years.

Catlin is best known for being the man that developed the test for the detection of Tetrahydrogestrinone that led to a number of athletes linked to the Bay Area Laboratory Co-Operative, including Britain's Dwain Chambers and the United States' Marion Jones, being caught in one of the biggest doping scandals in history.

Disgraced American cyclist Lance Armstrong also employed Catlin in an effort to prove his innocence back in 2009, when he was initially dogged by rumours that he used banned performance-enhancing drugs.

UCLA provided anti-doping testing at Los Angeles 1984, Atlanta 1996 and Salt Lake City 2002 - three American editions of the Olympic Games.

UCLA is due to be the site of the Athletes' Village at the 2028 Olympic and Paralympic Games in Los Angeles, although the laboratory is based at a different site.