Ratepayers have paid an administration fee of about $15,000 for his contract and contributed $19,841 to the family's relocation costs.
Last night, a spokeswoman for the mayor said Mr Brown had been unaware of Mr Jenkins' job in London.
However, Mr Brown came out in support of the contract after being briefed today by officials at Auckland Tourism, Events and Economic Development (Ateed).
"We are united as one city to face the international stage and bring major opportunities to the city that could not have happened before," he said.
"In areas like tourism and events, Ateed has already achieved this on behalf of Auckland Council. We need to work beyond our sister cities into major financial and economic hubs, sometimes with visits and delegations, and on occasions with project placements in market.
"Our goal is to aggressively grow international investment and revenues into Auckland which is completely consistent with our Auckland plan."
Waitemata Local Board chairman Shale Chambers said on social media that "the appointment is a really bad look and frankly undefendable".
The former council employee who contacted the Weekend Herald about Mr Jenkins' new role said it was a case of a "job for the boys".
"His wife is English and has been very openly longing to return to live there for several years.
"Ateed's senior leaders, in their wisdom, have decided that they should concoct a role for him, pay to set him and his family up and live in one of the world's most expensive cities at the Auckland ratepayers' cost.
"No one had the opportunity to apply for this role. It was never advertised, just announced and put in place. It is stomach turning."
This is the second time this week the mayor has been blindsided by council bodies. He knew nothing about Ports of Auckland plans to begin demolishing Marsden Wharf next week.
Brett O'Riley, head of Ateed, said the council body hatched a 12-month pilot project in London to attract skilled workers to Auckland and contracted Mr Jenkins to Tourism New Zealand.
He said Mr Jenkins indicated the family were moving back to England and resigned last year.
"About that time, we were looking at what we were going to do with this whole area and so it seemed a good opportunity for us to get someone who knows Auckland well to be driving this activity for us, rather than hiring a contractor in the UK to do it.
"I think we are getting good value for money compared to the alternatives."
Mr O'Riley said Mr Jenkins was working as a contractor, not an Ateed employee. Mr Jenkins' LinkedIn page says he started as the Auckland programme manager (London) for Ateed last October.
Mr O'Riley said the job was not advertised internally because there was no certainty it would last longer than 12 months, and the cost of having to move someone to the UK.
Mr O'Riley said Ateed took account of how the London job might look to Auckland ratepayers, who are facing hefty rates increases and cuts to core services in a new 10-year budget.
"We are driven by what are the demands of the business community and employers here and how do we grow the economy. At the moment our shortage of skilled workers is our biggest challenge," he said.
The London job was entirely consistent with Ateed's statement of intent, Mr O'Riley said, which was to grow the economy, develop a skilled workforce and attract new money and jobs into Auckland.
Councillor Cameron Brewer called the contract a "racket" that needed to be shut down immediately.
"Last year, we agreed to narrow down and more strategically focus our international relationships. London did not even come close.
"The mayor and councillors agreed that Asia and the Pacific would remain the focus, but once again no one's listening to elected representatives, let along the poor old tortured ratepayers.
"Communities facing project and service cutbacks have been told there's no wastage in the organisation and the council is a lean machine focused on core business. Here's one example which blows that spin completely out of the water."
