UPDATE: The AFL will launch an investigation into Lance Franklin's proposed move to the Sydney Swans, who are believed to have offered the star forward $10 million over nine years.

Perhaps wary after last year's Kurt Tippett controversy, when the Adelaide forward was eventually suspended for the first half of the season because the Crows broke salary cap and draft rules, the AFL announced on Tuesday the Franklin deal would also be scrutinised.

"The AFL advises that no binding player contract offer can be made until the commencement of the Free Agency Period on Friday 4 October 2013," AFL spokesman Patrick Keane announced via Twitter.

"AFL says key people involved in proposed L Franklin arrangement will be interviewed in coming days to ensure in accordance with AFL Rules. Under enhanced compliance measures, this is now standard procedure and is a process that will be followed for all Free Agency lodgements."

Keane also announced that the AFL was reviewing the controversial cost of living allowance for the two Sydney clubs, which gives each almost $1 million extra to lure and retain players in what they claim is a more expensive market.

"Separately, all club and player allowances, including the cost of living allowance, are currently being reviewed by the AFL," Keane said.

Suggestions that Sydney’s offer to Franklin could top $10m over nine years have been backed up by a statement released by Greater Western Sydney saying the Giants could not match the Swans’ offer.

Giants CEO David Matthews said Franklin had been offered a deal of $1.2m a year for six years but confirmed the club had been advised by Franklin’s manager Liam Pickering that he intended to accept an even more lucrative offer from the Swans.

"We put forward what we believed to be both a sensible and attractive offer to Franklin. Contrary to media reports, that offer was $1.2 million a year over six years," he said.

"It appears he has a significantly higher financial offer which we would not have been prepared to make based on our due diligence. We have every confidence in our list management strategy but we cannot compromise it for the sake of one individual.

"We have been patient and shown a lot of respect through the process.  This decision now allows us to pursue other options during the forthcoming trade period.

"With the right experienced players alongside the likes of Jeremy Cameron and Jonathan Patton we have every confidence we can achieve significant on field improvement in the years to come."

Hawthorn released a statement on Tuesday evening. "After discussions with Lance Franklin earlier today and Strategic Management this afternoon, Hawthorn Football Club understands that Franklin has decided to explore his options under free agency," the Hawks said.

"Under AFL rules, the Club recognises that as a restricted free agent Franklin may consider offers from rival clubs during the Free Agency Period that can be matched by Hawthorn FC. Hawthorn Football Club will continue to apply its established list management strategy that puts the needs and interests of the Club first.’’

The Swans simply said: ‘‘We are pleased that Lance has expressed his desire to join the Swans."

Former Hawthorn president Jeff Kennett said Franklin would leave with the club's blessing considering the money on offer but said it would be wrong if he was allowed to pocket any extra cash for spruiking the sport in the northern market, as rugby league converts Karmichael Hunt and Israel Folau had been given.

If Franklin had gone to GWS, it is widely expected his salary would have been topped up by the AFL for ambassadorial duties.

"Firstly, I hope the AFL are not going to pay him marketing (ambassadorial) monies on top of his salary. That would be a total breach of the concept of providing marketing money for what we would call newer clubs, GWS and Gold Coast," said Kennett on Fox Sports.

Kennett also questioned the future of Sydney's cost of living allowance.

"Secondly, I think there is an issue over the 10 per cent cost of living that Sydney claims," continued Kennett. "I think the presidents of all clubs have got to call the AFL to account and the AFL has got to be able to prove the extra 10 per cent of salary cap in terms of cost of living has been spent by Sydney every year."