Pound-for-pound king Floyd Mayweather Jr is reportedly trying to prove that his ex-girlfriend Josie Harris was on drugs during an altercation back in 2010.

In May, Ms Harris filed a $20m (£13m) lawsuit against the American boxer claiming defamation, intentional infliction of emotional distress and negligent infliction of emotional distress.

The legal action is in relation to an interview that Mayweather did with Katie Couric in April, in which he claimed that he did not punch Ms Harris, but restrained her while she was under the influence of drugs.

Following the altercation, Mayweather served two months of a three-month jail sentence after pleading guilty to a reduced charge of misdemeanor battery and two counts of harassment.

Now, according to TMZ, the sportsman has filed documents stating that he has medical records proving that Ms Harris was taking Xanax, Wellbutrin and marijuana at the time.

Mayweather has added that Ms Harris admitted in 2004 to taking half an ecstasy pill before going clubbing.