Apple is planning to say that the European Union’s investigators unfairly kept their investigation into Apple’s tax practices quiet, and more specifically, failed to say that they had changed their focus before hitting Apple with a massive tax fine, Bloomberg is reporting, citing sources who claim to have knowledge of Apple’s plan. Ireland will join Apple in appealing the fine and will also say that the investigators should have revealed that they had shifted focus.

The news comes approximately a month after the European Union slapped a $14.5 billion tax bill on Apple (AAPL), alleging that the company, through a sweetheart tax deal with Ireland, was able to shield itself from paying more taxes on profits over the last several years. Apple quickly rebuffed the accusations saying it had done nothing wrong. Ireland, which could generate billions on the fine, stands with Apple in opposing the EU. The case could go on for years before a final ruling comes down.

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The EU started its investigation into Apple’s tax practices in 2014. The investigators said at that time that they were focusing their investigation on transfer pricing agreements, or deals between different units within a company that allows the company (in this case, Apple) to sell goods and services between divisions. Ultimately, the transfer pricing aims at getting the most taxable income to countries where tax polices are most advantageous. In Apple’s case in Europe, that has been Ireland, which charged Apple as little as 0.005% on corporate taxes—much lower than the 12.5% tax rate the EU believes Apple should have paid under Ireland’s statutes.

However, when the EU announced its fine last month, it made no mention of Apple engaging in transfer pricing. Instead, European Competition Commissioner Margrethe Vestager’s investigation and fine focused on how Apple allegedly shifted the bulk of its European profits to “head offices” that are not subject to tax under the Eurozone’s regulations.

According to Bloomberg‘s sources, Apple had a right to know that the investigators were changing their tack and focusing on head offices instead of transfer pricing. Those sources also told Bloomberg that when Apple and the Ireland government tried to learn more about the shift in focus, investigators wouldn’t hand over critical information.

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“The commission changed course a number of times and has taken all sorts of steps to obscure that fact from us and from the Irish,” Apple general counsel Bruce Sewell said in a statement to reporters last month after the EU’s fine came down. “We were not given the opportunity to defend this case in the way that we should’ve been.”

European Commission spokesman Ricardo Cardoso told Fortune that Apple was indeed kept informed of the investigative activities.

“The investigation in this case has proceeded in exactly the same way as all State aid investigations. We have followed all standard procedures,” Cardoso said. “There was no change in the investigation. It has been the same investigation from the start until now. The aid measures under investigation are the two rulings of 1991 and 2007 and this is clearly explained in the decision to open the investigation. The rulings endorsed an internal allocation of profits within Apple Sales International and Apple Operations Europe, between their respective head offices and branches, allowing Apple Sales International and Apple Operations Europe to pay very little tax on its profits. This gave Apple a significant benefit compared to other businesses, in breach of EU state aid rules.”

Cardoso added that its investigation was based on “facts” there given to the European Commission by Apple. “This cannot therefore be new to Apple,” Cardoso added.

It’s unclear whether claims that the Commission’s investigators didn’t act fairly will hold up in court. However, Apple might also have itself to blame for not knowing what was happening during the course of the investigation.

Earlier this week, The Wall Street Journal cited its own sources who said that Apple had an anemic lobbying effort in the EU that left the company in the dark about key shifts in the probe. The report found Apple spent 900,000 euros (about $1 million) on EU lobbying last year. In comparison, Google (GOOG), which is having its own investigation troubles with the EU, spent 4.25 million euros during the period. The Journal‘s sources said the lobbying would’ve done little to affect the outcome, but could have given Apple useful information to prepare for the levy.

But now the damage is done, and all Apple can do is appeal the fine and hope for the best.

Apple did not respond to a request for comment.

Update at 1:45 p.m. ET to include the European Commission’s statement.