CuseFan is correct, there is no prohibition and it is reported as taxable compensation to the employee. But first, read the document/agreement.
It is not uncommon for the document/agreement to contain a 409A Gross-Up Payment clause spelling out terms and conditions of such a payment. For example, you may find provisions specifying timing of the gross-up payment and the tax year of the individual in which the gross-up will be paid and be taxable income, specifying how the gross-up will be calculated, specifying obligations of the individual to work with the company to contest the claim or to cooperate with the company's legal counsel, and other related details.