Gallagher, an ICAEW member, was convicted of assaulting his wife Anne Marie Gallagher in July, according to the Financial Times.
He pleaded not guilty to the charges at magistrates in Newcastle Upon Lyme, later appealing the court’s decision.
The appeal was recently dismissed and Gallagher ordered to do 80 hours community work. He was also issued with a restraining order regarding his wife.
This led to his removal as CFO at Northgate on Tuesday.
Gallagher joined Northgate in February last year, having previously been Spirit Pub Company group CFO and he held senior roles at the likes of Dell, Rank and Wang International.
Scientific Digital Marketing Imaging non-executive director David Tilston has replaced him as interim CFO until a permanent replacement is found.
Tilston is also an ICAEW member and was recently an interim CFO at Consort Medical and Innovia Group.