Report: NFL angry with leaked contracts ahead of free agency

The NFL isn't happy that so many details of the contracts slated to be signed when free agency officially begins Tuesday are being leaked ahead of time.

The league sent a letter to all 32 teams stating its displeasure with the release of contract terms, according to Yahoo Sports' Rand Getlin. 

The letter states that the league will conduct an investigation to examine whether teams have infringed on the collective bargaining agreement by agreeing to terms with impending free agents before they are permitted to.

Players whose contracts will expire on Tuesday are permitted to negotiate with all teams in a three-day "legal tampering" window ahead of the start of free agency, but they are not permitted to agree to deals.