HELSINKI, Aug 23 (AFP) - Finland's prime minister Sanna Marin apologised on Tuesday (Aug 23) for a controversial photo taken at her residence, less than a week after the 36-year-old sparked criticism with a video of her partying.

The picture circulated by Finnish media shows two women kissing, lifting their tops to bare their torsos and covering their breasts with a sign that says "Finland".

Marin confirmed on Tuesday the picture was taken at her official residence in Kesaranta, after she attended a music festival that took place Jul 8-10.

"I think the picture is not appropriate, I apologise for it. Such a picture should not have been taken," Marin told reporters in Helsinki.

Marin said she had "friends" at her residence at the time "spending the evening" and "going to the sauna".

The picture was first published on a TikTok account by a former Miss Finland contestant and social media influencer, who appears in the photo.

An editorial in the Nordic country's largest newspaper Helsingin Sanomat on Tuesday said Marin did not appear to be "in control", and more pictures and videos from her private life could end up in the public domain.

Marin made headlines across the world last week when a video surfaced showing her dancing and partying with a group of friends and celebrities.

Some interpreted comments heard on the video as referring to narcotics, something heavily debated on social media and which she strongly denied.

Spurred by the controversy, Marin took a drug test on Friday to "clear up suspicions".

Her urine sample was tested for the presence of various drugs. It came back negative.

"Drug test taken from Prime Minister Sanna Marin on 19 August 2022 did not reveal the presence of drugs," Marin's office said on Monday, adding that the results were signed by a doctor.

Her dancing in the video has also been criticised by some as inappropriate behaviour for a prime minister, while others have defended her right to enjoy a private event with friends.

So far Marin has had the support of her party, with Antti Lindtman, head of the Social Democratic Party's parliamentary group, telling media he "can't see any major problem with dancing at a private event with friends".

Marin - who was appointed in 2019 at the age of 34 - has previously been the target of criticism over parties at her official residence.

In December 2021, she came under sustained criticism after it was revealed she stayed out dancing until the early hours despite having been exposed to COVID-19.