What do you mean under "this is not my income"?
Is that a loan? a gift? other?
If you do not owe the money, but your relative does - he/she need to obtain taxpayer's ID from the IRS for the business entity your relative is planning to invest.
As the account owner - in case you transfer the money to US - if the amount is more than $100,000, you are required to file form 3120 - http://www.irs.gov/pub/irs-pdf/f3520.pdf (see instructions for details - http://www.irs.gov/pub/irs-pdf/i3520.pdf) to declare transfer from the foreign country. There is no tax associated with this form.
As you do not own the money - it is not your income and you do not need to include that amount into your tax return.