“Even those of us who want to do the right thing can fall foul of dodgy operators,” Andersson told the Expressen newspaper on Saturday after it reported on the arrest, which took place just before Christmas after one of the cleaners accidentally set off a security alarm. 

Andersson said that the owner of the cleaning firm had assured her on multiple occasions that all of his employees were working legally under salaries and conditions set by a union collective bargaining agreement. 

“I have now cut all contacts with the cleaning firm. They have on several occasions answered in the affirmative when asked if they had signed up to a collective bargaining agreement with the unions,” she said. “I now expect the responsible agencies to get to the bottom of what happened.”

The opposition Moderate Party, who has named the emerging scandal Städgate or “cleaner-gate”, argued on Saturday that the situation raised serious questions about Andersson’s security arrangements. 

The party’s parliamentary group leader Tobias Billström told Expressen it was “serious and worrying that the country’s prime minister could end up in such a situation”. 

“The main question now is whether this a one-off event or whether there other similar examples,” he said.

There was a real risk, he added, that immigrants without valid documents working for senior politicians could be blackmailed by hostile foreign powers. 

In the UK, he wrote out on Twitter, an immigration minister found to have used an immigrant cleaner who was in the country illegally was forced to resign. 

I Storbritannien får ministrar avgå när de blir påkomna med att ha olagligt invandrad arbetskraft anställd. pic.twitter.com/Z06EMwmwR4

— Tobias Billström (@TobiasBillstrom) January 8, 2022

On December 21st, police came to the house in Nacka, outside Stockholm, where Andersson has lived with her family since 2011, after one of the two cleaning ladies working at the house had accidentally set off an alarm.

They discovered that one of the two cleaners working that day, a 25-year-old woman from Nicaragua, not only lacked both a residency permit and a work permit, but that border police were searching for her so that she could be deported.

“We checked one person and it turned out that person had received a deportation order, after which we handed that person over to the Migration Agency,” Tommy Kalenius, who leads the police in Nacka, told Expressen.

Since taking over as Prime Minister at the start of December, Andersson has moved to Sweden’s official prime minister’s residence at Sagerska huset opposite the Royal Palace in Stockholm, and she had already moved out by the time of the police visit. 

The cleaning woman admitted to police that she had been working illegally after receiving a deportation order in the spring of 2020. The woman was also found guilty of stealing goods from the Åhléns department store in Stockholm in the autumn of 2020, but was not jailed as it was a first offence. 

The head of the cleaning company said that the woman had been supplied by one of the two other cleaning companies to whom he sometimes subcontracts work. He told Expressen that his company had never had a collective bargaining agreement with a union. 

In 2010, the company’s owner was found guilty of sending fake invoices and inventing front companies to lower his tax bill, for which he was fined 600,000 kronor and given a one-year prison sentence.

He managed to win his case at appeal, however, arguing that the suspect invoices were real and had been sent to a woman called “Svetlana”, whose surname he had forgotten.

Andersson has made clamping down on Sweden’s black economy one of the major focuses of her leadership, saying it is up to each individual to check that everyone they buy goods and services from is legitimate. 

In her comment to Expressen, she said that the episode only served to underline her point.

“Like many other Swedes, I am careful to make sure that everything is right and proper when I buy in services,” she wrote.

“But that even those of us who want to do the right thing can fall foul of dodgy operators shows that we need to carry on pushing through even more political measures to fight the various forms of cheating.”