Cavaliers probing Heatâs signing of James http://sports.yahoo.com/nba/news;_ylt=AmQl4ZGdw1JgCgKZuPlxQdi8vLYF?slug=aw-gilbertlebron120110 CLEVELAND â The Cleveland Cavaliers have poured hundreds of thousands of dollars into a high-powered Midwestern law firm to investigate their suspicions that the Miami Heat broke NBA tampering rules while pursuing LeBron James(notes), and owner Dan Gilbert has privately vowed he wonât relent until he has a thick binder of findings to drop on the desk of the NBA commissioner, league sources told Yahoo! Sports. The NBA wonât launch an investigation into a tampering case without a formal request from a team, but sources say Gilbertâs plan is to give commissioner David Stern a detailed case that includes meetings, phone calls and contingency plans that date as far back as 2008. Gilbert will implore Stern to use his powers as commissioner to get access to phone records and testimony of key people surrounding Heat president Pat Riley, James and others potentially involved. Cavs owner Dan Gilbert has hired a law firm to investigate whether the Heat violated NBA rules in their recruitment of LeBron James. Gilbert has spent several hundred thousand dollars on the investigation and will spare no expense to uncover whatever evidence he can to take to the league office, two sources with direct knowledge of the probe told Yahoo! Sports. The law firm staff includes several former prosecutors with backgrounds in investigating and constructing cases, sources said. Prior to the start of free agency on July 1, no Miami Heat representative â including star Dwyane Wade(notes) â was allowed to discuss with James the specific circumstances around Wade, Torontoâs Chris Bosh(notes) and James joining together with the Heat. One focus of the law firmâs probe includes an alleged Riley-James meeting in Miami in November 2009, and a meeting of Jamesâ inner circle with Wade in Chicago in June 2010, sources said. Riley, James, Wade and Bosh have denied there was a predetermined collusion in the historic free-agent binge, although the players have admitted to discussing the possibility of playing together as far back as the 2008 Olympics in Beijing. When approached about the story on Tuesday night at Clevelandâs Quicken Loans Arena, Gilbert declined to answer questions from Yahoo! Sports. As one league source told Yahoo! Sports: The Cavs are âdetermined to get everything out there. Theyâre not letting go of this. Theyâre not going to just let this die.â Potential penalties for tampering could include front-office suspensions, fines and losses of draft picks. Many teams are suspicious of the league officeâs desire to investigate these kind of cases because of the potential embarrassment to the league. This revelation makes for one more dramatic storyline to Jamesâ return to Cleveland on Thursday night. Gilbert escalated Clevelandâs fervor over losing James when he issued a scathing email about James on the night of the two-time MVPâs television decision. For that diatribe, Stern fined Gilbert $100,000.