Getting an inactive instagram handle and recovering a lost account.

Hello,

I am in contact with the owner of an Instagram handle that i am after for my business, he is willing to accept a small sum of money for the account however he is struggling to get access.

When he uses the forgot password option, it sends him a link to reset to his phone, luckily his number is current, But it then takes it to his current account. Assuming this is because both his and the inactive account are attached to the same number.

I am wondering if anyone had any solutions or have deal with a similar issue, and whether the only way that this can be resolved would be buying a trademark and providing this to instagram so they release the handle.

Kind regards,