The National Party has also seized upon what it says is a lack of demand for the properties, 50,000 of which are planned for Auckland.
"The ballot closed for the first houses in Wanaka and Te Kauwhata last month. Across these developments only four of the 20 houses sold, a worrying sign given the Minister has agreed to buy almost 400 houses across the two sites," Opposition Housing spokesperson Judith Collins said this week.
An automatic message on Barclay's email and cellphone refers people to Brad Ward for all KiwiBuild inquiries. Ward is at the Ministry of Housing and Urban Development.
Neither KiwiBuild's spokeswoman, nor a spokeswoman for Housing and Urban Development Minister Phil Twyford would answer questions about Barclay's departure.
A spokesman for the Ministry of Housing and Urban Development said Barclay is "currently away from the office".
Asked when he would be back, the spokesman said: "The Ministry doesn't comment on matters relating to individuals."
KiwiBuild launched with the intention of building 100,000 "affordable" homes in New Zealand over the next ten years – 50 per cent off them in Auckland. It is designed to increase home ownership.
Housing Minister Phil Twyford came under fire in October after admitting the programme was not for low-income families.
His comments came after it was revealed some of the buyers of the first completed homes were professionals, including a newly graduating doctor and marketing manager.
Barclay started in the powerful, newly-created role on May 28, splitting his time between Auckland and Wellington and telling the Herald during winter that he was ready for the challenge.
"I had to be persuaded because I haven't been in the government sector for a long time and then only for two years. I made it a condition that I had to talk to the Minister," he said in July when he praised Twyford.
"I found someone [Twyford] I could really work with. He valued my opinion. I could talk frankly with him," he said in July.
On KiwiBuild's achievability, Barclay said: "Absolutely, we can build 100,000 in 10 years because the industry is constrained by things that are solvable: building material prices; skills and land supply shortages; land prices and building methodologies. It's about making a whole bunch of changes and about how we use the KiwiBuild balance sheet."
Barclay was previously at the Ministry of Health, where he was chief people and transformation officer, and before that chief executive of the San Francisco America's Cup Events Authority.