A Syrian-born British woman says she has been denied entry to Australia without explanation.

Zahra Ramadani, 30, who lives in London, had hoped to be in Sydney for the New Year's Eve fireworks before travelling around New Zealand for about two weeks.

She said she received notification that her application for an Electronic Travel Authority (ETA) was successful, but was later told it had been revoked and she was not eligible for a visa to Australia.

"I went to check-in [for my flight], and I got an email from the High Commission saying it had been overruled and that I was not eligible for a visa to Australia," she told the ABC.

"I asked what was wrong. I got a reply saying it was issued in error and it needed further time for processing."

An ETA can be obtained via airlines and travel agents for visits to Australia of up to three months.

Ms Ramadani said she had applied for another type of visa, an eVisitor visa, on Monday, but had not received a response.

She said she called the Australian High Commission and was told to apply for a ETA because "maybe they could get it through faster".

"[The eVisitor visa] form was really complicated," she said.

"I rang my friend and told her I needed her details, because I was asked for my companion's details, my employer's details, it was very ridiculous."

Ms Ramadani said the questions on her application were very different to those of her friend, who is also British but born in Bahrain.

"She entered Bahrain [as her place of birth], which is also a Muslim country. Her page two was very different to mine. Bear in mind that we're both British, both not born in the UK," she said.

"She got an automated response saying it was all fine. I didn't hear anything.

"When I asked [the High Commission] why I had a different form to my friend's in the first place, I didn't get a response. For me, the suspicion started there.

"The last time I went to Syria was about six or seven years ago. I've never had any problems. No convictions, nothing."

When contacted, a spokesperson from the Department of Immigration and Border Protection said "the individual has made two separate applications for two different visas to enter Australia".

"In such circumstances the department needs to resolve the different visa applications," the statement said.

"The department is in contact with the individual applicant and is working to resolve the application."

This week, the relatives of a terminally ill Pakistani man were granted visas to Australia after their applications were initially declined.