Sofia City Prosecution and the State Agency for National Security (SANS) descended on the Ministry of Agriculture and Food and the State Forestry Agency to investigate documents relating to documents regarding forest and land transfers, a media statement from the prosecutor's office said.

According to Bulgarian daily Dnevnik, none of the top ministry officials were in the building at the time of the investigation.

Recent changes in Bulgaria's Forestry Act introduced a moratorium on transactions of land and forests.

Prosecutor Nikolai Roussinov announced on March 18 that initiation of pre-trial proceddings against an unknown perpetrator. The aim was to establish whether the ban on exchanges of land and forests had been breached, Roussinov said.

"We are checking all cases. We have information that documents may have been manipulated and are looking into whether or not that is true," Roussinov was quoted by Dnevnik as saying.

According to Bulgarian broadcaster mediapool, NGO coalition For the Nature said in January that while the amendments to the Forestry Act were prepared for publication in the Sate Gazette, the Sate Forestry Agency (SFA) had realised it had applications for transactions dating back to 2005, 2006 and 2007.

The NGOs accused Stefan Yuroukov, head of the SFA, of signing applications after Parliament approved the moratorium on January 16 2009, and said he would continue to sign transactions until the moratorium would be in force.

Yuroukov said that he is obliged to sign the transactions and that some of the transactions were impeccable, Dnevnik said.

In its latest report on Bulgaria, the European Commission said it would closely monitor whether the legislative changes effectively prohibited transactions with land and forests.

Agriculture Minister Valeri Tsvetanov, who at the time of the prosecution checks was in Plovdiv for the opening of Vinaria 2009 fair, declined to comment and said he was not familiar with the matter. Tsvetanov said he would answer after his return to Sofia.