Marius Tsakov, deputy governor of the Sofia region and a senior member of the National Movement for Stability and Progress, was arrested on September 24 2008 in possession of a large amount in marked banknotes, an alleged bribe.

Bulgarian National Television (BNT) said that the sum was 6000 euro, Bulgaria's Focus news agency said that it was 6000 leva while news website mediapool.bg said that it was $6000.

BNT quoted prosecutors as saying that Tsakov had been arrested in a special operation after attempting to extort 25 000 euro from a construction contractor. The contractor alerted authorities who were present when the money, allegedly the first instalment of the bribe, was handed over.

According to BNT, Tsakov changed the meeting place for the handover of the money several times.

Tsakov (48), a physician by training, is a former hospital employee, tax inspector and a former deputy mayor of Botevgrad. He was a founder member of Simeon Saxe-Coburg's NMSP, which as the National Movement Simeon II was the majority partner in government from 2001 to 2005 and currently is a member of the post-2005 governing tripartite coalition.

Prosecutors said that Tsakov was being held in 72-hour detention for questioning, but given the severity of the alleged offence, they would ask for him to be held in custody pending a trial.

The NMSP said that if found guilty, Tsakov would be expelled immediately. "The NMSP does not hold a political umbrella over anyone," NMSP deputy chairperson Marina Dikova was quoted by Focus news agency as saying.

The Tsakov arrest was the second high-profile detention in Bulgaria in as many days, following the September 23 detention by the State Agency for National Security of Ivan Lekov, deputy head of the State Agency for Youth and Sport, in connection with alleged abuse of office.