"Pealtnägija," a leading investigative TV program, has reported on how MPs divvy up the approximately 10 million euros that Parliament deputies can channel at their discretion each year.
Rather than purely benefiting the public interest, the ETV program said, the money often goes to advance personal and party causes, sometimes even for such expenses as summer houses.
The tradition of placing such a fund in the control of MPs dates from the mid-1990s. At that time, it was a bid by the Cabinet to prevent the country's painstakingly balanced budget from be torn apart by MPs looking to satisfy special interests.
The slang word for the fund used by both the "Pealtnägija" reporters and critics, and perhaps current MPs, echoes organized crime terms - katuseraha, or protection money.
"Pealtnägija" relied mainly on interviews with ex-MPs - whistleblowers like Marek Strandberg, the Green Party leader who has been vocal recently in his criticism of the Reform Party-led coalition.
Strandberg said that the money tends to be split between the coalition parties and the opposition at a ratio of about 3:1.
For a long time the slush fund was a hush fund, said the journalists, but in 2006 the protection money was used to try to buy electoral college members. Back then, Mihkel Oviir, now the auditor general, criticized the lack of transparency in how the money was distributed to local governments. But it was a Center Party politician, Heimar Lenk, who blew the cover on the issue a year later when he distributed gifts to voters and the press picked up on it.
The fund was reduced to zero during the recession but was soon reinstated, rising to 9.5 million euros in 2013.
"I think the tradition can't be banned as every MP says that it is a completely legal procedure. But it isn't fair as all taxpayers are not treated equally," said Strandberg.
It is hard to find the line item in a given budget. It often changes places from one year to the next. In 2012, it was listed under "additional section for other appropriations allotted to government departments and state institutions administered by government departments," but in 2013 it showed up in a different place.
On paper, everything seems legitimate - the recipients include many NGOs. But many of them are connected to politicians, said "Pealtnägija," citing numerous examples.
IRL was a particularly brazen offender, said the reporters, with NGOs founded or supervised by party members often getting donations.