Jose Aldo taunts Conor McGregor and calls him an 'Irish sucker' after taking a drug test ahead of their UFC 194 title showdown

The UFC featherweight champion posted the snap of himself holding up a certificate from the United States Anti Doping Agency (USADA), presumably a response to McGregor's past insinuations that the Brazilian had used performance enhancing drugs.

UFC returns to London and Michael Bisping, Brad Pickett and Ross Pearson are hoping to feature at O2 Arena show in February

Ronda Rousey thrills Australian UFC crowd ahead of her 'biggest challenge' against boxing world champion Holly Holm at the Etihad...

Conor McGregor could be the UFC's best featherweight but I can still beat him, says fellow Ultimate Fighter coach Urijah Faber

Demetrious Johnson dominates John Dodson to defend flyweight title at UFC 191

Paige VanZant continues impressive impact on UFC with victory over Alex Chambers

Conor McGregor and Jose Aldo almost come to blows during UFC's 'Go Big' launch

Paige VanZant in no hurry to carve her name into UFC history books ahead of duel with Alex Chambers on Saturday 

Life's a beach for UFC star Conor McGregor as heavily-inked fighter shows impressive balance ahead of Jose Aldo rematch

Ronda Rousey goes shopping with friends as UFC star is all smiles after saying 'yes' to military man who asked her to the Marine...

Conor McGregor lives up to 'notorious' nickname by adding more tattoos to his heavily-inked body while out in California

Conor McGregor poses in convertible Bentley before stopping off in tattoo shop as UFC star enjoys life in California

Ronda Rousey's fight with Holly Holm moved forward to November at UFC 193 at Melbourne's 55,000-seat Etihad Stadium 

Floyd Mayweather and Ronda Rousey feud rages on as boxer challenges UFC star: 'Let's see how much money you got!'   

Max Holloway earns seventh consecutive win as early injury forces Charles Oliveira out of UFC Saskatoon main event 

UFC featherweight prospects Max Holloway and Charles Oliveira to determine the future of the division in Saskatoon

UFC icon Ronda Rousey is a man among women... she is a super freak and super athlete, claims WWE star Brock Lesnar

UFC star Paige VanZant chills out with Cryotherapy session ahead of upcoming fight with Alex Chambers  

Ronaldo Souza and Yoel Romero to fight on Jose Aldo and Conor McGregor card at UFC 194 in Las Vegas

Anderson Silva suspended for one year and fined £240,000 after testing positive for banned substances during pre-fight test

Paige VanZant shows off her dangerous 'Ninja kick' as UFC star films new advert