Finnish Prime Minister Sanna Marin has apologised for a photograph taken of two other women shown kissing during a party at her official residence following a rock festival.

“The picture is inappropriate and should not have been taken,” Marin said during a press conference on Tuesday in Helsinki with President Sauli Niinisto.

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The photograph shows two women kissing while covering their naked breasts with a sign with “Finland” inscribed on it.

Marin, 36, has been at the centre of controversy in Finland after videos published last week showed Marin dancing with friends at a private event.

The videos led to questions about whether she had taken drugs, but Marin rejected all the allegations and underwent a test, which turned up negative on Monday.

Asked at the press conference whether national security could have been compromised during the night in question, Niinisto said: “I don’t believe that anything out of the ordinary happened that night.”

The 36-year-old Marin has repeatedly said that she has had never used drugs, explaining that when partying with her friends, she only drank alcohol.

The video images have divided the country, triggering a debate among Finns about what level of revelling is inappropriate for a prime minister, especially considering neighbouring Russia’s attack on Ukraine, which prompted long-neutral Finland and Sweden to apply for NATO membership.

But the prime minister, who is married and has a four-year-old daughter, emphasised her right to spend her free time in the same way others her age do - and women around the world have posted videos of themselves dancing, using the hashtag #solidaritywithsanna.

“I hope that in the year 2022 it’s accepted that even decision makers dance, sing and go to parties,” Marin told reporters. “I didn’t wish for any images to be spread, but it’s up to the voters to decide what they think about it.”