Bulgarian authorities have detained and dismissed two road transport inspectors after they allegedly demanded bribes from truck drivers carrying equipment for Robbie Williams' Sofia concert, highlighting ongoing corruption concerns in state agencies.

This is the latest in a series of corruption allegations facing Bulgarian state institutions, with the Road Safety Institute claiming multiple previous signals about corrupt practices have gone unaddressed. Occurring ahead of Williams' concert at Vasil Levski stadium in Sofia, the incident drew both domestic criticism and international attention to corruption issues within Bulgarian transport enforcement agencies.

The UK-registered trucks were stopped on September 26, with inspectors reportedly requesting cash before allowing them to proceed. Following complaints to the British Embassy and Bulgarian authorities, the inspectors were detained and charged with bribery.

Transport Minister Grozdan Karadjov said the inspectors, who had worked in the system since 2012, were immediately removed and faced disciplinary proceedings. He called the incident "a remnant of an outdated culture of corruption."

The Institute for Road Safety sent an open letter to Karadjov following the incident, stating the organisation has repeatedly signalled corrupt practices in the Executive Agency "Automobile Administration" without response from the Ministry of Transport.

"The latest case from a few days ago is particularly worrying - IAAA officers stopped two trucks with English registration, transporting equipment for the Robbie Williams concert, and tried to extort a bribe from the drivers," the institute wrote.

"Despite the seriousness of the case and the risk of an international scandal, the ministry is silent. Mr Karadjov, you are usually active in the public space - why are you silent now?" the letter continued.

The institute criticised what it described as "silence, darkness and lack of transparency in road safety management" as reasons why government efforts do not yield results, demanding a clear position and concrete actions from the minister.