Mayor Bill de Blasio will be questioned voluntarily by federal prosecutors Friday in connection to fundraising activities for his campaign.

An official familiar with the matter said that it is a voluntary interview. The mayor has had extensive preparation this week ahead of the meeting.

Mayor de Blasio has not been subpoenaed. It is something of a tightrope walk for the mayor who has volunteered to answer questions, but has not been granted immunity from prosecution.

Today’s meeting comes as the U.S. Attorney’s office potentially wraps up a lengthy investigation into the mayor’s fundraising and campaign activities.

De Blasio voluntarily agreed to sit down with federal investigators and he has not requested or been offered immunity to do so.

His office says the mayor and his aides have always acted appropriately.

The mayor is also under investigation by the Manhattan District Attorney’s office in connection with state senate campaigns he assisted in 2014.

Mayor de Blasio will be accompanied by counsel at the interview.

(Source: WABC.com / NY1)