Der Spiegel claims one of City's solutions to circumvent the rules was to launch Project Longbow.
The magazine said the name "Longbow" was chosen, according to City's chief legal adviser, Simon Cliff, as it was "the weapon the English used to beat the French at Crecy and Agincourt" in the Hundred Years' War.
With the help of investment experts David and Jonathan Rowland, father and son, City are said to have transferred the player marketing rights to Fordham Sports Management. Usually clubs pay players for their image rights. Arabtec workers had gone on strike in May 2013, which was said to have resulted "in violence and deportations" and there had also been reports about the dire conditions in Abu Dhabi for migrant workers.
According to Der Spiegel, Guardiola's original contract with City was dated October 10, 2015 - more than three months before the deal was announced on February 1, 2016.
Der Spiegel cited Man City documents in which officials wrote: "Without significant additional revenues". This was followed up by further claims on Monday and Tuesday, including suggestions sponsorship deals with Abu Dhabi-based companies were topped up by discrete payments from City's owner Sheikh Mansour.
However, a spokesperson for Etihad has claimed the airline was the real source of the money it paid to City.
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La Liga president Javier Tebas has long spoken out against Manchester City and PSG describing their conduct as financial doping and La Liga spokesman Joris Evers told Reuters and the BBC the time for action is needed.
When UEFA were investigating City over FFP, Fordham apparently never came up.
On Friday, Der Spiegel disclosed how Infantino did a secret deal over FFP sanctions with City's Abu Dhabi owners and Paris St-Germain's Qatari owners while he was general secretary at UEFA.
Gianni Infantino, the Federation Internationale de Football Association president, was alleged at the weekend to have struck a secret deal with the club when he was at Uefa which meant they avoided a Champions League ban.
City have not commented on the stream of claims beyond referring to a statement they issued last week which read: "We will not be providing any comment on out of context materials purportedly hacked or stolen from City Football Group and Manchester City personnel and associated people".
Asked whether this is what City had been doing, manager Pep Guardiola said there was a lot more to it than that.
"Believe me, I'm completely honest, I don't know what happened, because I am a manager, I am focused about what happened on the pitch, and locker room".
"I think it's the biggest single risk to (our) reputation we have faced since 2008", she is said to have written.