Concerns have been raised about changes to the way Freedom of information (FoI) requests are handled in Scotland.
All Scottish government FoI requests are now published online after complaints about late responses.
The Scottish Liberal Democrats say journalists have been put off making requests because rivals get the answers at the same time.
Ministers insist it shows Scotland has one of "the most open and transparent governments in the world".
The Freedom of Information (Scotland) Act gives everyone the right to ask for any information held by a Scottish public authority, with a response required within 20 working days.
Some information can be exempt but an organisation must explain the exemption which applies.
The Lib Dems claim the new system of open publication is "devaluing the information".
MSP Tavish Scott said ministers had "figured out they can evade scrutiny, deter the submission of requests and spike stories".
There has been a row over Scotland's freedom of information system after a group of journalists signed an open letter voicing concerns.
In June, MSPs unanimously condemned the Scottish government's performance on FOI requests and called for an independent inquiry.
In response, the Scottish government announced it would publish all information released in response to FoI requests online from July.
Mr Scott said: "Ministers accepted a degree of criticism of their performance.
"However, the only measure they have really championed to address the fact they weren't responding properly to freedom of information requests, publicly publishing all material released under FoI, is fraught with dangers of its own.
"Just weeks into the new regime I am hearing from journalists that this is having a chilling effect on their work. We need quality investigative journalism to acquire the truth and get to the bottom of spin. These changes are designed to deter that.
"Immediately publishing information publicly removes the incentive for journalists to pursue stories as they fear that whatever they uncover will immediately be made available to all their competitors.
"This wheeze means the Scottish government can appear transparent while achieving the opposite."
Mr Scott called for an independent inquiry into how the Freedom of Information system operated.
He added: "There is a good argument that information released under FoI laws should be in the public domain. However, the best process for doing this should be considered as part of a wider independent inquiry.
"For example, a short delay between the provision of the information to the applicant and it being published could make the system fairer.
"Meanwhile, the original problem of industrial scale evasion and the failure to release information we have a right to remains. Just this week, my party had to again chase up information that was asked for 17 weeks ago."
The Scottish government said FoI legislation has been extended to extra public bodies and that access to national records has been reduced from 30 years to 15 as part of a drive to improve transparency.
A spokesman for Parliamentary Business Minister Joe FitzPatrick said: "This is an extraordinary statement from Tavish Scott, who is suggesting that the Scottish government is now releasing too much information, implying that we should instead cut back on the amount of material we release.
"Under this government, freedom of information has been extended, and Scotland now has one of the most open and transparent information and governance systems, which has been praised internationally."