Butcher was told in May that he could leave London Road

The 26-year-old has signed a two-year contract, and the Magpies will not have to pay an initial transfer fee.

Chief executive Geoff Davey told County's website: "We haven't paid a fee up front, but an arrangement in the deal suits us very well.

"If Richard is transferred away, there is a situation where Peterborough could benefit," he explained.

Butcher was one of several players who were told by Posh boss Darren Ferguson in May that they could leave London Road.

He had moved there on a free transfer in June 2006 from Oldham after spells with Rushden & Diamonds, Kettering and Lincoln, and made 49 appearances in his season with Posh, scoring five goals.