Premiership Rugby will be allowed to access texts, emails and bank statements of players and club officials to maintain the integrity of a salary cap system and avoid another scandal that led to former champions Saracens being relegated this year.
Saracens, winners of four Premiership titles in the past six years, were sanctioned for spending above the league's £7 million salary cap and were docked points before being relegated from the top flight this season.
Premiership Rugby's salary cap manager Andrew Rogers said he would scrutinise communications such as emails, text messages, WhatsApp messages of club officials as well as at least half of all players' tax returns and bank statements.
"Each year the champion club will be given an extended audit. This is a far more forensic audit," Rogers said.
"There is now a greater obligation on all participants to consult with me and there is also a greater list of areas that need pre-approval from me, whether it is a player sponsorship deal or testimonial.
"There is a real emphasis there on transparency. There are sanctions in place for non-cooperation."
However, Rogers said there were limits to his powers and that it would not be easy to police clubs.
"We're not a law-enforcement agency," Rogers added. "The key club officials all have to sign a declaration to say they will comply with the regulations and notify any breaches.
"The whistleblower policy is there and available and the players have to provide tax returns. There will always be some elements, I'm sure, where somebody quite clever gets around it."
Meanwhile, Premiership Rugby clubs agreed to reduce the salary cap for the 2020-21 season, with spending limited to £6.4m. The cap will be further reduced to £5m for the 2021-22 campaign.
The updated regulations follow a comprehensive review led by former government minister Paul Myners, who proposed an overhaul of the salary cap following persistent breaches by Saracens.
The new Premiership season begins later on Friday.