Theresa May is to raise concerns with Donald Trump after evidence from the Manchester Arena bombing was apparently leaked to US media.
UK officials were “furious” when photos appearing to show debris from the attack appeared in the New York Times.
The prime minister is expected to raise the issue with the US president when they meet at a Nato summit later.
Monday night’s attack at Manchester Arena killed 22 people – including children – and injured 64.
BBC security correspondent Gordon Corera says UK officials believe that US law enforcement rather than the White House is the likely culprit for the leaks.
The meeting between the two leaders, at a Nato summit in Brussels, will take place as British police continue to investigate an alleged “network” linked to suicide bomber Salman Abedi.
Early on Thursday morning, detectives carried out a controlled explosion as they searched a property in the Moss Side area of Manchester.
Six men, including Abedi’s older brother, and a woman were arrested in a series of raids across Manchester, Wigan and Nuneaton.
She was subsequently released without charge in the early hours of Thursday.
Abedi’s father and a younger brother have been detained by militia in Libya.
Publication of photographs, including a device described as a “possible detonator” by the New York Times, prompted a furious response from within Whitehall and from UK police chiefs.
Details about Abedi’s identity had already emerged in the US media less than 24 hours after the explosion.
Home Secretary Amber Rudd said she was “irritated” by the disclosure and had warned Washington “it should not happen again”.
Despite that plea, the photographs – which were later reproduced in the UK media and appear to show bloodstained fragments from the bomb and the backpack used to conceal it – were published afterwards.



