Slovenia's interior minister resigned and the economy minister was detained on Tuesday in connection with an investigation into alleged irregularities in the purchase of protective gear during the new coronavirus pandemic.

Announcing his resignation, Interior Minister Ales Hojs said he had only been informed about the probe that day, claiming it was launched to discredit and bring down the current four-party centre-right coalition government.

"I think this is a politically motivated action," Hojs told journalists, adding that the police chief had also resigned in protest over the action, which he said was solely the initiative of the country's special police forces.

Slovenian media have reported numerous alleged irregularities during the acquisition of protective equipment and respirators shortly after a new centre-right government was appointed in March.

They have accused Economy Minister Zdravko Pocivalsek of favouring some companies that did not offer adequate equipment. Pocivalsek has denied any wrongdoing.

Special police forces searched several houses Tuesday as part of an ongoing "investigation over alleged irregularities in the order and acquisition of protective gear", they said in a statement.

While the police did not mention Pocivalsek, Hojs said he was informed the minister had been detained.

Slovenian media reported that Pocivalsek was released late Tuesday.

Since taking office, Prime Minister Janez Jansa has introduced strict confinement measures to contain the COVID-19 outbreak and started acquiring personal protective gear and respirators, claiming the previous government had left the EU member unprepared for the pandemic.

Jansa himself on Tuesday dismissed the special police forces' "double standards" and "selective approach", claiming they had failed to investigate other cases.

Thousands have thronged Ljubljana every Friday for two months in protest over the protective gear scandal, as well as government attacks against critical media and journalists.