If the irs is holding my refund for further review (as stated in a letter sent from the irs) how long should I expect to wait for my refund?

[Critter]

There is no set time frame ... the notice probably said they needed 60 days. They will send you another letter if they want anything else. 

[Jtkezar]

And it's 60 days from the date of the letter not from when you filed