The BBC's home affairs correspondent was accused yesterday of trying to downplay the suspect's reported Somali origins.
As Dominic Casciani covered the crime, social-media users claimed he was 'desperate to diminish implications of a Muslim Somali immigrant killing an MP'.
Although every national newspaper with the exception of the Financial Times mentioned that the suspect had Somali 'origins', 'heritage' or 'descent' yesterday, Casciani appeared to wrestle with the issue on Radio 4's Today programme.
Presenter Nick Robinson asked him: 'The suspect is a British citizen, but he's also of Somali origin. Is that regarded as significant?'
Casciani replied: 'The Somali element – erm, no. The reason why some reporters have established this fact is that there has been some misreporting.
The BBC's home affairs correspondent Dominic Casciani was accused yesterday of trying to downplay the suspect's reported Somali origins
'Yesterday, during the day, there were some news outlets, and also on social media, some suggestions as to the identity of the individual.
'So I think the police are at pains to clarify in a statement last night that the individual is British.
'They haven't said anything about the heritage. But my understanding is that there was initially, potentially, some confusion over the individual's background and identity.'
Twelve hours earlier, he had tweeted: 'We have learnt from official sources that detectives have established the individual is a UK national, seemingly of Somali heritage. We report this in the interests of accuracy.'
Many people on Twitter queried his use of the words 'seemingly' and 'accuracy', and some commented that he was 'whipping up xenophobia'.
The BBC says Casciani 'focuses on stories relating to law, order, society and belonging – including immigration, ethnicity'.