Two Metropolitan police officers have been arrested after a photograph was allegedly taken of the bodies of murdered sisters in a London park, the Guardian has learned. Nicole Smallman, 27, and Bibaa Henry, 46, were found stabbed to death in Fryent country park in north-west London this month. They were the daughters of a pioneering cleric, Mina Smallman, the Church of England’s first female archdeacon from a black and minority ethnic background. The sisters were reported missing after a birthday gathering on 5 June, and their bodies were found on 7 June. Police said several days later that they had been stabbed to death by a stranger who was likely to have been injured in the attack and who is still at large. Smallman was a freelance photographer. Henry was a social worker and mother of one. A criminal inquiry is under way into the conduct of two officers over claims that an “inappropriate” photograph was taken at the murder scene and allegedly sent to a group of people that included members of the public. The Guardian understands that other photos were also taken, including one showing a police officer. The allegations were reported to the Met’s directorate of professional standards, which referred them to the Independent Office for Police Conduct (IOPC), which is investigating. The watchdog described the allegations as sickening. The investigation will consider whether any criminal charges should be brought or any disciplinary offences apply. The family of the two women have been told about the photograph and are said to have been shocked and distressed. The IOPC said: “The investigation relates to allegations that inappropriate photographs were taken at a homicide crime scene and subsequently shared with a small number of others. The Metropolitan police service is handling matters involving those members of the public who may have received those images. “Two Metropolitan police constables were arrested by IOPC investigators on Monday 22 June and have been bailed to a later date pending further enquiries.” Sal Naseem, the IOPC director for London, said: “These are sickening allegations and when we were made aware by the Metropolitan police we acted quickly to arrest the officers involved in order to seize vital evidence. The victims’ family are naturally extremely distressed at this turn of events.” The IOPC is also investigating whether police bungled their search and inquiries after the women were reported missing. Henry and Smallman had gathered in a park with friends at about 7pm on 5 June to celebrate Henry’s birthday. They are believed to have stayed behind after their friends left just after midnight, and last had contact with family and friends at 1.05am. They were reported missing the following day. Commander Paul Brogden, of the Met, said: “I am horrified and disgusted by the nature of these allegations, a sentiment which will be shared by colleagues throughout the organisation. If true, these actions are morally reprehensible. “This deeply disturbing information will no doubt have created additional trauma for a family who are already grieving the devastating loss of two loved ones. I can only start to imagine the impact of this, and I’d like to sincerely apologise to them for this further burden. “I know that the wider community will share our shock and repulsion at these allegations and whilst our focus remains with Bibaa and Nicole’s family we are also listening to the concerns our communities and key stakeholders will want to raise about these allegations.” The mayor of London, Sadiq Khan, said: “Londoners will be undoubtedly disgusted by these sickening allegations and I am deeply concerned about the impact this will no doubt have on the victims’ family, friends and the wider community.” The two officers have been suspended from duty. DCI Simon Harding, who is leading the murder inquiry, previously said of the sisters’ last evening: “They were in good spirits and taking selfie pictures, listening to music and dancing with fairy lights until at least 1.13am. “Those lights created a distinctive pattern ... This in itself may have been noticeable to local residents and other users of the park. Did you see the lights at the time and if so can you remember where you were and whether you saw anything suspicious?” Police say phone calls to the two women went unanswered from about 2.30am. Detectives believe the killer suffered a “significant injury” during the attack. The Met said in a statement: “These are very serious allegations and the MPS has been and will continue to provide every possible support to the IOPC investigation team as they work to establish the facts.” Anyone with information can call the incident room on 020 8721 4205, via 101 or tweet @MetCC quoting CAD 3160/7Jun. Alternatively, information can be provided online via https://mipp.police.uk/operation/01MPS19Z02-PO1. Information can be provided anonymously via the independent charity Crimestoppers on 0800 555 111.