A rapper who attended a celebrity party with only a sock to hide his modesty has been jailed for 15 days, sponsors of some of Russia's best known entertainers have torn up their contracts, and President Vladimir Putin is reported to be unamused.

An "almost naked" party at a Moscow nightclub held at a time when Russia is engaged in a war with Ukraine and the authorities are pushing an increasingly conservative social agenda, has provoked an unusually swift and powerful backlash.

A video clip of Putin's spokesperson listening to an explanation from one of the stars who attended has been circulating online, and Baza, a news outlet known for its contacts with the security services, has reported that troops fighting in Ukraine were among the first to complain after seeing the footage and that photographs of the event reached an unimpressed Putin.

Dmitry Peskov, Putin's spokesperson, on Wednesday asked reporters to forgive him for not publicly commenting on the burgeoning scandal, saying: "Let you and I be the only ones in the country who aren't discussing this topic."

Maria Zakharova, a spokesperson for the Russian Foreign Ministry, said that the event had "stained" those who took part, but that they now had a chance to work on themselves, according to the Ura.ru news outlet.

The fierce backlash from the authorities, pro-Kremlin lawmakers and bloggers, state media, and Orthodox Church groups has been dominating the headlines for days, displacing stories about rising egg prices and inflation.

The party, in Moscow's Mutabor nightclub on Dec 21, was organised by blogger Anastasia (Nastya) Ivleeva and was attended by well-known singers in various states of undress who have been staples on state TV entertainment programmes for years.

Ivleeva, who has since become one of Russia's most recognised names and who attended wearing jewellery worth 23 million roubles ($251,000) at a time when some Russians are struggling to get by, has issued two public apology videos.

In the second tearful one, released on Dec 27, she said she regretted her actions and deserved everything she got but hoped she could be given "a second chance."

Her name has since disappeared as one of the public faces of major Russian mobile phone operator MTS, the tax authorities have opened an investigation that carries a potential five-year jail term, and a Moscow court has accepted a lawsuit from a group of individuals demanding she pay out 1 billion roubles ($10.9 million) for "moral suffering."

If successful, they want the money to go to a state fund that supports Ukraine war veterans.

'CYNICAL'

"To hold such events at a time when our guys are dying in the (Ukrainian) special military operation and many children are losing their fathers is cynical," said Yekaterina Mizulina, director of Russia's League for a Safe Internet, a body founded with the authorities' support.

"Our soldiers on the front line are definitely not fighting for this."

Many of the party's famous participants have recorded apologies, including journalist Ksenia Sobchak whose late father Anatoly used to be Putin's friend and boss.

The scandal comes at a time when Putin, who is expected to comfortably win another six-year term at a March election, has doubled down on social conservatism, urging families to have eight or more children, and after Russia's Supreme Court ruled that LGBT activists should be designated as "extremists."

Nikolai Vasilyev, a rapper known as Vacio who attended wearing only a sock to cover his penis, was jailed by a Moscow court for 15 days and fined 200,000 roubles ($2,182) for propaganda of "non-traditional sexual relations."

Other more famous names have had concerts and lucrative state TV airtime cancelled, contracts with sponsors revoked, and, in at least one case, are reportedly being cut out of a new film.

The scandal has angered those who support Russia's war in Ukraine.

One woman who said her nephew had lost both legs in combat wrote in a post to the League for a Safe Internet that the stars should pay for prosthetic legs for her relative and others to make amends.

"That would be a better apology," the unidentified woman wrote.