What do we know about alleged Trump signature on Epstein letter?

A "birthday letter" to Jeffrey Epstein from 2003, allegedly signed by Donald Trump, has been released by US lawmakers.

The White House has said, "the president did not write this letter, he did not sign this letter", but Democrats believe it is authentic.

There has been a particular focus on the signature - BBC Verify's Jake Horton has been examining it, with the help of handwriting experts.

Produced by Aisha Sembhi. Graphics by Leo Scutt-Richter.