Depositing this money into the IRA is an excess contribution to the extent that you cannot treat it as a regular traditional IRA contribution. To eliminate the excess contribution and avoid the 6% excess-contribution penalty you must request that the IRA custodian make a return of contribution before the due date of your tax return, including extensions (not a regular distribution).
There will be no double taxation. The only part of the distribution from the traditional IRA that would be taxable and potentially subject to early-distribution penalty are any gains attributable to the returned amount which are required to accompany the returned amount.
