Police investigating the mass sexual assaults in Cologne on New Year’s Eve claim they were ordered to remove the word “rape” from their initial report.

Local officers had produced an internal “important event” memo entitled “rape, sexual harassment, thefts, committed by a large group of foreign people” – the first indication of the scale of the incident which would go on to make headlines around the world.

According to Cologne newspaper Express, officers received a phone call from the state police control centre ordering them to take down the report “or otherwise delete the phrase ‘Vergewaltigung’” – “rape”.

A senior Cologne police officer told Express he was informed of the order by a colleague who took the call, and that state police understood it to be “the wish of the state interior ministry”.

The allegation of a political cover-up puts serious pressure on North Rhine-Westphalia interior minister Ralf Jäger, in a scandal which has already seen Cologne police chief Wolfgang Albers forced into early retirement.

Express published a letter it had received from a high-ranking Cologne policeman, named as Joachim H, who was on duty on New Year’s Day and described his colleague receiving the order.

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

Police ultimately refused the request, leaving the word “rape” in their report, and the news would eventually reach the wider world.

According to German media reports, opposition politicians in NRW state are calling for Mr Jäger to be sacked.

The interior minister was due to address an interior policy committee meeting on Thursday, and his spokesman said he would answer questions on the new reports then.

He denied a cover-up, but confirmed “professional discussions” had taken place between state controllers and Cologne police over the “classification” of the New Year’s Eve assaults.