Norman's departure, first reported by Bloomberg critic Richard Vines, was confirmed yesterday (11 August) via a 'termination of appointment' noticed filed on Companies House.
According to a Tweet by Vines, Norman said that "things change", but would not discuss the matter further.
BigHospitality has reached out to Norman for comment.
A former English teacher and operations director at Caprice Holdings, Norman founded Polpo with friend Richard Beatty.
The group opened its first Venetian-inspired restaurant in Soho in 2009, and subsequently expanded to six London sites as well as establishing regional locations in Bristol, Brighton and Exeter.
It also launched a number of offshoot brands including Spuntino; Da Polpo; Polpetto and Mishkin’s.
However, a varied history has subsequently led to much of the group's estate closing.
Last year the business underwent a company voluntary agreement (CVA) following a combination of over-investment in head office infrastructure, and focus on “expensive but ultimately ineffective” marketing initiatives in 2018.
At the time, it put its Polpetto sites in Soho and Notting Hill Gate up for sale.
It has since placed two of its London Polpo sites – in Farringdon and Covent Garden – on the market, and closed its remaining regional site in Brighton.
Spuntino's original site on Soho's Rupert Street was also closed last year.
Polpo currently operates two remaining sites: its flagship Beak Street restaurant in Soho, which reopened last week; and in Chelsea’s Duke of York Square.