This is definitely unethical, as David Ingram states. The validity of any test depends on it being used within its design parameters. Whether you are validating a flight simulator, accrediting a training course, or measuring language skills, the tools for measuring must be appropriate to what you are measuring.

From the article:

David Ingram, a linguist who is one of the designers of IELTS, agreed and said it was not meant to be used as an immigration test.

“It concerns me greatly,” he said. “And as a person who’s spent a lot of his life working in the area of testing, it seems to me that it is unethical to be using tests that have been developed for one purpose, for another.”
Mr Ingram feels so strongly about the issue he has written to an Australian government productivity inquiry warning of a skills shortage unless skilled migrants are able to choose between a wider range of tests.

English test derailing Irish dream of Australian citizenship

A stringent English language test is delaying or denying many Irish people from getting Australian citizenship. The test difficulty got national exposure because of the case of Co Tipperary man Kevin Wall.

This is definitely unethical, as David... - Mike Smith Teacher | Facebook

This is definitely unethical, as David Ingram states. The validity of any test depends on it being used within its design parameters. Whether you are...