A music producer who used to work with Jay Z is under investigation by police in New York and Los Angeles over an alleged extortion plot regarding a number of the rapper's master recordings. The hip-hop mogul recorded the tracks for his Roc-A-Fella Records between 1998 and 2002, but the masters went missing in 2002 and were subsequently presumed lost. However, Chauncey Mahan recently contacted Jay Z's business partners at Live Nation, who work with the star on his Roc Nation label, and allegedly offered to sell them a number of masters he had stored away in Northridge, California for $100,000 (£62,500). The two parties agreed to a fee of $75,000 (£46,875), and arranged to seal the deal at the storage facility on Friday (18Apr14), according to TMZ.com. However, instead of meeting Jay Z's representatives, Mahan was confronted by police. He was not arrested, but agreed to accompany cops to the station for questioning. The masters were also taken away for safe keeping until ownership can be determined. The extortion allegations are currently under investigation by authorities in Beverly Hills, where Live Nation is based, while Jay Z's team has filed a separate complaint for grand larceny with New York officials over claims the masters were illegally removed from their Big Apple offices.