Chael Sonnen’s fight with Vitor Belfort at UFC 175 has been scrapped after Sonnen failed a pre-fight drugs test in Nevada ahead of the July 5th event.

Sonnen is reported to have tested positive for the illegal substances Anastrozole and Clomiphene, both classified as anti-estrogenic drugs.

This latest spanner in the works comes just weeks after his original opponent Wanderlei Silva was pulled from their fight after failing to take the same random drugs test, and just days after Belfort came clean and admitted that he had failed a separate random drugs test back in February.

Both Sonnen and Belfort had legally been using Testosterone Replacement Therapy by way of a Therapeutic Use Exemption up until February when the Nevada State Athletic Commission announced that the the treatment was now banned.

This is not the first time that Sonnen has failed a drugs test. He was suspended for a year in 2010 (later reduced to six months) after being found to have testosterone levels well above the legal limit following his first fight with Anderson Silva.

At this stage a punishment for his latest failed test has not been established. Sonnen hasn’t commented on the situation so far, but is expected to do so later today.