"extensive audit" is correct and usable in written English.
You can use it when referring to an in-depth examination or review of something, such as financial accounts. For example, "The company conducted an extensive audit of their finances."
Eventually the Internal Revenue Service conducted an extensive audit of her.
We will be keeping a close watch on the progress Google makes and will follow up with an extensive audit.
Legislators had requested the information on Union's trust funds to carry out an extensive audit of the government's $76 billion bailout of banks after the 1995 peso crisis.
Following an extensive audit, we are writing to a number of companies to tell them their current systems do not conform to the new code.
"The evidence we will present to the O.S.C. will show that Ernst & Young Canada did extensive audit work to verify ownership and existence of Sino-Forest's timber assets".
According to a fact sheet provided by the theater, since the crisis came to light the board has raised $874,315 in cash, created a 2011 budget that cuts over $1.4 million from the previous year's budget, established a plan to pay back rent and started an extensive audit.
Such extensive auditing would be beyond local capacity.
Since 2007, Apple had built one of the most extensive auditing programs in the electronics industry, inspecting over 800 facilities.
Salleh said 1MDB had undergone extensive audits since 2009 and the $4bn figure "simply could not have been misappropriated under such conditions".
The companies send in engineers and specialists to conduct extensive audits of each district — Energy Education uses a checklist of 1,200 items — and then custom-design conservation programs.
The panel also suggested that extensive auditing functions should be built into the system to ensure that Carnivore is used to gather only information allowed in a particular case.
