The head of a police department in Blagoevgrad, southwestern Bulgaria, has been removed in a row that began after the arrest of a construction company owner over an insult to Prime Minister Boyko Borisov.

Interior Minister Rumyana Bachvarova has asked for the resignation of Rosen Tanushev, arguing he had "exceeded police powers" by allowing the detention of Metodi Bachev, the owner of a construction company named Agromach, who used a public gathering to make offensive statements about Borisov.

In the video, Bachev is seen issuing his remarks apparently under the influence of alcohol.

Bachev was arrested after the footage was published by a local news agency.

He later filed a complaint with police, saying it was "unacceptable" to air his comments which were outside the public part of the event.

His detention went on for 12 hours, according to the Bulgarian National Radio.

The news website Dnevnik.bg quotes prosecuting authorities as saying it had not asked for the detention, but had instead demanded his release as there had been no grounds for him to be arrested.

However, police claimed Bachev was summoned to give explanation at the request of the regional prosecutor's office.

On Thursday, in an interview for private bTV station, Borisov commented on the case, saying: "Drunkards can say whatever they want, but it is then politicians [who are accused of] blabbering nonsense and then wonder how to say "sorry" in the court.