Ousted FBI Director James Comey declined an invitation from the Senate Intelligence Committee to testify in a closed session on Tuesday, committee aides told Politico on Friday.

No immediate explanation was given for his refusal.

The panel had asked Comey to appear so they could question him about the circumstances of his firing and other topics, most likely including the ongoing FBI probe into possible Russian ties to President Trump.

The president, Vice President Mike Pence and administration spokespeople have offered a dizzying variety of reasons for Comey’s ouster.

Trump said it was at least partly based on his frustration over the Russia probe, which he called “fake news.”

But Pence and his reps insisted days earlier that Comey was fired solely on the recommendations of Attorney General Jeff Sessions and his top deputy.