The Australian is reporting the result of major contractors to pass on the benefits of the scheme has been subcontractors refusing to sign up to the NBN, while those that do are often less experienced.
One anonymous subcontractor told the newspaper a major NBN Co contractor was charging the government around $106 a metre for drilling, while offering to pay subcontractors a rate of around $38 a metre.
"High gross margins are being gouged out by the big companies and are the main contributing reason for the rollout issues for the NBN," the subcontractor said.
NBN Co spokeswoman Rhonda Griffin said subcontractors were employed by "our construction partners" and not NBN Co directly, saying that NBN Co and the federal government had little control over the rates being chargedd.
"We expect these construction companies - made up of the leading players in the industry - to manage their subcontractor arrangements reasonably and pay fair rates," Ms Griffin said.
Communications Minister Stephen Conroy has said however that the delay will be made up by the completion date of 2021.