heard it said

[kingston_123]

Peter, I've heard it said, used to be a drag queen before he took up body building.

What does "it" refer to?

 

[Matthew Wai]

I think it refers to 'Peter used to be a drag queen before he took up body building'.
'I've heard it said' = 'I've heard it said by someone'.

 

[Skrej]

Yes, with the construction of "I've heard it said', 'it' refers to the information being reported.