President Joe Biden's ghostwriter Mark Zwonitzer may not used to being center stage - but that is exactly where the unassuming writer has found himself.

Zwontizer has kept his head down and his mouth shut since it emerged last Thursday that the Department of Justice considered charging the 61-year-old author with obstruction of justice on learning that he had destroyed recordings and notes of interviews during which President Joe Biden shared classified information.

Seen in these exclusive pictures obtained by DailyMail.com, Zwonitzer broke cover Friday afternoon.

He cut a slim and casual figure, dressed in navy jacket and pants, as he left his New York apartment to run an errand.

Approached by DailyMail.com Zwontizer was polite but determined, saying only that he 'could not' talk when asked about the DoJ investigation into which he has been drawn.

Bespectacled and lightly bearded with greying hair and a professorial demeanor, Zwonitzer is an unlikely figure to be embroiled in a classified documents scandal.

Yet he is so close to the 81-year-old president that Biden has said he would trust the writer with his life.

In a way, he has done just that - twice – by making Zwonitzer ghostwriter of his memoirs, first in 2007 with 'Promise to Keep,' and second, ten years later with, 'Promises to Dad.'