Etherington was part of the £4million deal that saw Freddie Kanoute sign for Spurs and the wing-back move to Upton Park, but Posh are upset at the £500,000 figure that is being quoted as Etherington's valuation in the deal.
"I spoke to David Pleat and he told me the deal was worth £4million of which Matthew was valued at £500,000," Peterborough boss Barry Fry told the Posh official website.
"I spoke to David Pleat and he told me the deal was worth £4million of which Matthew was valued at £500,000," Peterborough boss Barry Fry told the Posh official website.
"A week or so before that Matthew was going to Charlton in a £5million deal with Scott Parker where Matt was valued at £1.5million.
"How on earth has his value gone down that much in just a week? We have made our feelings known and it is up to the governing bodies to sort it out."
The wing-back moved to White Hart Lane from London Road for £500,000 in 1999 and Spurs agreed to pay Peterborough 15 per cent of any future sale above that figure.