A cartoon “etiquette guide” supposedly created for migrants using swimming pools in Germany was in fact produced in 2013 and predates the current refugee crisis, Munich officials have said.

The images, showing a red cross over a hand reaching out to touch a woman in a bathing costume, have been circulating on social media and featured prominently in German media reports.

It came amid very real reports that local officials in the small town of Bornheim near Cologne had banned refugees from using a public pool, citing recent reports of sexual harassment and “chatting up”. The pool re-opened later after the measure was widely condemned.

But the cartoons themselves are at least two years old, and feature a broad range of guidelines for swimming pool use including messages of tolerance.

Rather than being produced in response to the spate of sex attacks on women on New Year’s Eve in Cologne, a Munich city spokeswoman told the DPA news agency the leaflets have been around since 2013, amid general concerns about anti-social behaviour across its 18 public pools.

“The ground rule of respect for women – whatever clothing they're wearing – is unfortunately not respected by all our swimmers. That's why there is an explicit indication about it,” the spokeswoman said.

Chancellor Angela Merkel is under increasing pressure to reduce the numbers of refugees reaching Germany and voters are growing doubtful that the state can tackle the crisis, her key ally and Finance Minister Wolfgang Schaeuble said on Monday.

Germany reacts to Cologne New Year's Eve attacks Show all 13 1 /13 Germany reacts to Cologne New Year's Eve attacks Germany reacts to Cologne New Year's Eve attacks Women protest against sexism outside Cologne Cathedral on 5 January after the assaults Oliver Berg/EPA Germany reacts to Cologne New Year's Eve attacks Women protest against sexism in Cologne following the rash of sex attacks on New Year's Eve Wolfgang Rattay/Reuters Germany reacts to Cologne New Year's Eve attacks Police initially failed to mention the assaults in report the following morning EPA Germany reacts to Cologne New Year's Eve attacks Police officers patrol in front of the main station of Cologne, Germany AP Germany reacts to Cologne New Year's Eve attacks German far-right supporters demonstrate at Cologne`s train station (Reuters) Reuters Germany reacts to Cologne New Year's Eve attacks Supporters of anti-immigration right-wing movement Pegida in Cologne, Germany, January 9, 2016. Reuters Germany reacts to Cologne New Year's Eve attacks Police used pepper spray to control supporters of Pegida, Hogesa (Hooligans against Salafists) and other right-wing populist groups as they protested against the New Year's Eve sex attacks on 9 January, 2016 in Cologne, Germany Reuters Germany reacts to Cologne New Year's Eve attacks Police use a water cannon during a protest march by supporters of anti-immigration right-wing movement Pegida in Cologne, Germany, January 9, 2016 Reuters Germany reacts to Cologne New Year's Eve attacks Police use pepper spray against supporters of anti-immigration right-wing movement Pegida, in Cologne, Germany, January 9, 2016. Reuters Germany reacts to Cologne New Year's Eve attacks Artist Mira Moiré protests naked in Cologne against the mass sex attacks on New Year's Eve AP Germany reacts to Cologne New Year's Eve attacks A demonstrator holds a sign in German that reads 'No violence against women' during a demonstration in the wake of the sexual assaults on New Year's Eve, outside the cathedeal in Cologne, Germany, 09 January 2016. EPA Germany reacts to Cologne New Year's Eve attacks Counter demonstrators hold up a sign reading "Against sexism, against racism" as they protest against a demonstration of the islamophobic movement PEGIDA at the train station in Cologne, Germany, on January 9, 2016. AFP/Getty Images Germany reacts to Cologne New Year's Eve attacks Demonstration by a women’s group on Saturday (AP) AP

Speaking at a panel in the western city of Duesseldorf, Schaeuble said it was "evident" that the pressure on Ms Merkel in the refugee crisis was bigger now than it was eight months ago.

Ms Merkel has promised to "measurably reduce" arrivals this year, but has refused to introduce a cap, saying it would be impossible to enforce without closing German borders.

Instead, she has tried to convince European partners to take on quotas of refugees, pushed for reception centres to be built on Europe's external borders, and led an EU campaign to convince Turkey to keep refugees from entering the bloc.